diff --git a/airtime_mvc/application/controllers/PlaylistController.php b/airtime_mvc/application/controllers/PlaylistController.php
index 64032d84a..65a9e38d8 100644
--- a/airtime_mvc/application/controllers/PlaylistController.php
+++ b/airtime_mvc/application/controllers/PlaylistController.php
@@ -30,6 +30,12 @@ class PlaylistController extends Zend_Controller_Action
 
     	if (isset($this->pl_sess->id)) {
             $pl = new Application_Model_Playlist($this->pl_sess->id);
+
+            $modified = $this->_getParam('modified', null);
+            if ($pl->getLastModified("U") !== $modified) {
+                $this->createFullResponse($pl);
+                throw new PlaylistOutDatedException("You are viewing an older version of {$pl->getName()}");
+            }
         }
         return $pl;
     }
@@ -51,6 +57,7 @@ class PlaylistController extends Zend_Controller_Action
         $this->view->name = $pl->getName();
         $this->view->length = $pl->getLength();
         $this->view->description = $pl->getDescription();
+        $this->view->modified = $pl->getLastModified("U");
 
         unset($this->view->pl);
     }
@@ -68,10 +75,33 @@ class PlaylistController extends Zend_Controller_Action
         }
     }
 
+    private function playlistOutdated($pl, $e)
+    {
+        $this->view->error = $e->getMessage();
+    }
+
+    private function playlistNotFound()
+    {
+        $this->view->error = "Playlist not found";
+
+        Logging::log("Playlist not found");
+        $this->changePlaylist(null);
+        $this->createFullResponse(null);
+    }
+
+    private function playlistUnknownError($e)
+    {
+        $this->view->error = "Something went wrong.";
+
+        Logging::log("{$e->getFile()}");
+        Logging::log("{$e->getLine()}");
+        Logging::log("{$e->getMessage()}");
+    }
+
     public function indexAction()
     {
         global $CC_CONFIG;
-        
+
         $request = $this->getRequest();
         $baseUrl = $request->getBaseUrl();
 
@@ -81,18 +111,16 @@ class PlaylistController extends Zend_Controller_Action
 		$this->_helper->viewRenderer->setResponseSegment('spl');
 
         try {
-            $pl = $this->getPlaylist();
-
-            if (isset($pl)) {
-              $this->view->pl = $pl;
+            if (isset($this->pl_sess->id)) {
+                $pl = new Application_Model_Playlist($this->pl_sess->id);
+                $this->view->pl = $pl;
             }
         }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
     }
 
@@ -119,20 +147,15 @@ class PlaylistController extends Zend_Controller_Action
 		}
 
 		try {
-            $pl = $this->getPlaylist();
+            $pl = new Application_Model_Playlist($id);
+            $this->createFullResponse($pl);
 		}
 		catch (PlaylistNotFoundException $e) {
-		    Logging::log("Playlist {$id} not found");
-            $this->changePlaylist(null);
+		    $this->playlistNotFound();
 		}
 		catch (Exception $e) {
-		    Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
-		    $this->changePlaylist(null);
+		    $this->playlistUnknownError($e);
 		}
-
-		$this->createFullResponse($pl);
     }
 
     public function deleteAction()
@@ -150,23 +173,18 @@ class PlaylistController extends Zend_Controller_Action
             }
             else {
                 Logging::log("Not deleting currently active playlist");
+                $pl = new Application_Model_Playlist($this->pl_sess->id);
             }
 
             Application_Model_Playlist::DeletePlaylists($ids);
-            $pl = $this->getPlaylist();
+            $this->createFullResponse($pl);
         }
-        catch(PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $pl = null;
+        catch (PlaylistNotFoundException $e) {
+            $this->playlistNotFound();
         }
-        catch(Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+        catch (Exception $e) {
+            $this->playlistUnknownError($e);
         }
-
-        $this->createFullResponse($pl);
     }
 
     public function addItemsAction()
@@ -176,24 +194,20 @@ class PlaylistController extends Zend_Controller_Action
     	$afterItem = $this->_getParam('afterItem', null);
     	$addType = $this->_getParam('type', 'after');
 
-    	Logging::log("type is ".$addType);
-
         try {
             $pl = $this->getPlaylist();
             $pl->addAudioClips($ids, $afterItem, $addType);
+            $this->createUpdateResponse($pl);
+        }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
         }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
-
-	    $this->createUpdateResponse($pl);
     }
 
     public function moveItemsAction()
@@ -201,46 +215,44 @@ class PlaylistController extends Zend_Controller_Action
         $ids = $this->_getParam('ids');
         $ids = (!is_array($ids)) ? array($ids) : $ids;
         $afterItem = $this->_getParam('afterItem', null);
+        $modified = $this->_getParam('modified');
 
         try {
             $pl = $this->getPlaylist();
             $pl->moveAudioClips($ids, $afterItem);
+            $this->createUpdateResponse($pl);
+        }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
         }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
-
-		$this->createUpdateResponse($pl);
     }
 
     public function deleteItemsAction()
     {
         $ids = $this->_getParam('ids');
         $ids = (!is_array($ids)) ? array($ids) : $ids;
+        $modified = $this->_getParam('modified');
 
         try {
             $pl = $this->getPlaylist();
             $pl->delAudioClips($ids);
+            $this->createUpdateResponse($pl);
+        }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
         }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
-
-		$this->createUpdateResponse($pl);
     }
 
     public function setCueAction()
@@ -253,21 +265,22 @@ class PlaylistController extends Zend_Controller_Action
             $pl = $this->getPlaylist();
             $response = $pl->changeClipLength($id, $cueIn, $cueOut);
 
-            $this->view->response = $response;
-
-            if(!isset($response["error"])) {
+            if (!isset($response["error"])) {
+                $this->view->response = $response;
                 $this->createUpdateResponse($pl);
             }
+            else {
+                $this->view->cue_error = $response["error"];
+            }
+        }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
         }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
     }
 
@@ -281,21 +294,22 @@ class PlaylistController extends Zend_Controller_Action
             $pl = $this->getPlaylist();
             $response = $pl->changeFadeInfo($id, $fadeIn, $fadeOut);
 
-            $this->view->response = $response;
-
             if (!isset($response["error"])) {
                 $this->createUpdateResponse($pl);
+                $this->view->response = $response;
+            }
+            else {
+                $this->view->fade_error = $response["error"];
             }
         }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
+        }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
     }
 
@@ -309,15 +323,14 @@ class PlaylistController extends Zend_Controller_Action
             $fades = $pl->getFadeInfo($pl->getSize()-1);
             $this->view->fadeOut = $fades[1];
         }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
+        }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
     }
 
@@ -335,15 +348,14 @@ class PlaylistController extends Zend_Controller_Action
             $pl = $this->getPlaylist();
             $pl->setPlaylistfades($fadeIn, $fadeOut);
         }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
+        }
         catch (PlaylistNotFoundException $e) {
-            Logging::log("Playlist not found");
-            $this->changePlaylist(null);
-            $this->createFullResponse(null);
+            $this->playlistNotFound();
         }
         catch (Exception $e) {
-            Logging::log("{$e->getFile()}");
-            Logging::log("{$e->getLine()}");
-            Logging::log("{$e->getMessage()}");
+            $this->playlistUnknownError($e);
         }
     }
 
@@ -351,33 +363,42 @@ class PlaylistController extends Zend_Controller_Action
     {
         $name = $this->_getParam('name', 'Unknown Playlist');
 
-        $pl = $this->getPlaylist();
-        if($pl === false){
-            $this->view->playlist_error = true;
-            return false;
+        try {
+            $pl = $this->getPlaylist();
+            $pl->setName($name);
+            $this->view->playlistName = $name;
+            $this->view->modified = $pl->getLastModified("U");
+        }
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
+        }
+        catch (PlaylistNotFoundException $e) {
+            $this->playlistNotFound();
+        }
+        catch (Exception $e) {
+            $this->playlistUnknownError($e);
         }
-        $pl->setName($name);
-
-        $this->view->playlistName = $name;
     }
 
     public function setPlaylistDescriptionAction()
     {
-        $description = $this->_getParam('description', false);
-        $pl = $this->getPlaylist();
-        if($pl === false){
-            $this->view->playlist_error = true;
-            return false;
-        }
+        $description = $this->_getParam('description', "");
 
-        if($description != false) {
+        try {
+            $pl = $this->getPlaylist();
             $pl->setDescription($description);
+            $this->view->description = $pl->getDescription();
+            $this->view->modified = $pl->getLastModified("U");
         }
-        else {
-            $description = $pl->getDescription();
+        catch (PlaylistOutDatedException $e) {
+            $this->playlistOutdated($pl, $e);
+        }
+        catch (PlaylistNotFoundException $e) {
+            $this->playlistNotFound();
+        }
+        catch (Exception $e) {
+            $this->playlistUnknownError($e);
         }
-
-        $this->view->playlistDescription = $description;
     }
 }
 
diff --git a/airtime_mvc/application/models/Playlist.php b/airtime_mvc/application/models/Playlist.php
index 441ed9a43..ee264df57 100644
--- a/airtime_mvc/application/models/Playlist.php
+++ b/airtime_mvc/application/models/Playlist.php
@@ -89,7 +89,7 @@ class Application_Model_Playlist {
     public function setName($p_newname)
     {
     	$this->pl->setDbName($p_newname);
-    	$this->pl->setDbMtime(new DateTime("now"), new DateTimeZone("UTC"));
+    	$this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
     	$this->pl->save($this->con);
     }
 
@@ -106,7 +106,7 @@ class Application_Model_Playlist {
     public function setDescription($p_description)
     {
     	$this->pl->setDbDescription($p_description);
-    	$this->pl->setDbMtime(new DateTime("now"), new DateTimeZone("UTC"));
+    	$this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
     	$this->pl->save($this->con);
     }
 
@@ -123,7 +123,7 @@ class Application_Model_Playlist {
     public function setCreator($p_id) {
 
         $this->pl->setDbCreatorId($p_id);
-        $this->pl->setDbMtime(new DateTime("now"), new DateTimeZone("UTC"));
+        $this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
         $this->pl->save($this->con);
     }
 
@@ -218,13 +218,18 @@ class Application_Model_Playlist {
     {
         $file = CcFilesQuery::create()->findPK($p_item, $this->con);
 
-        $entry = $this->plItem;
-        $entry["id"] = $file->getDbId();
-        $entry["pos"] = $pos;
-        $entry["cliplength"] = $file->getDbLength();
-        $entry["cueout"] = $file->getDbLength();
+        if (isset($file) && $file->getDbFileExists()) {
+            $entry = $this->plItem;
+            $entry["id"] = $file->getDbId();
+            $entry["pos"] = $pos;
+            $entry["cliplength"] = $file->getDbLength();
+            $entry["cueout"] = $file->getDbLength();
 
-        return $entry;
+            return $entry;
+        }
+        else {
+            throw new Exception("trying to add a file that does not exist.");
+        }
     }
 
     /*
@@ -300,7 +305,7 @@ class Application_Model_Playlist {
                 $pos = $pos + 1;
             }
 
-            $this->pl->setDbMtime(new DateTime("now"), new DateTimeZone("UTC"));
+            $this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
             $this->pl->save($this->con);
 
             $this->con->commit();
@@ -383,7 +388,7 @@ class Application_Model_Playlist {
 
 
         $this->pl = CcPlaylistQuery::create()->findPK($this->id);
-        $this->pl->setDbMtime(new DateTime("now"), new DateTimeZone("UTC"));
+        $this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
         $this->pl->save($this->con);
     }
 
@@ -415,7 +420,7 @@ class Application_Model_Playlist {
                 $contents[$i]->save($this->con);
             }
 
-            $this->pl->setDbMtime(new DateTime("now"), new DateTimeZone("UTC"));
+            $this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
             $this->pl->save($this->con);
 
             $this->con->commit();
@@ -462,47 +467,52 @@ class Application_Model_Playlist {
         $fadeIn = $fadeIn?'00:00:'.$fadeIn:$fadeIn;
         $fadeOut = $fadeOut?'00:00:'.$fadeOut:$fadeOut;
 
+        $this->con->beginTransaction();
+
         $errArray= array();
-		$con = Propel::getConnection(CcPlaylistPeer::DATABASE_NAME);
-
-        $row = CcPlaylistcontentsQuery::create()->findPK($id);
-
-        if (is_null($row)) {
-            $errArray["error"]="Playlist item does not exist.";
-            return $errArray;
-        }
-
-        $clipLength = $row->getDbCliplength();
-
-        if(!is_null($fadeIn)) {
-
-			$sql = "SELECT INTERVAL '{$fadeIn}' > INTERVAL '{$clipLength}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)) {
-                //"Fade In can't be larger than overall playlength.";
-                $fadeIn = $clipLength;
-            }
-            $row->setDbFadein($fadeIn);
-        }
-        if(!is_null($fadeOut)){
-
-			$sql = "SELECT INTERVAL '{$fadeOut}' > INTERVAL '{$clipLength}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)) {
-                //Fade Out can't be larger than overall playlength.";
-                $fadeOut = $clipLength;
-            }
-            $row->setDbFadeout($fadeOut);
-        }
 
         try {
-            $row->save();
+            $row = CcPlaylistcontentsQuery::create()->findPK($id);
+
+            if (is_null($row)) {
+                throw new Exception("Playlist item does not exist.");
+            }
+
+            $clipLength = $row->getDbCliplength();
+
+            if (!is_null($fadeIn)) {
+
+    			$sql = "SELECT INTERVAL '{$fadeIn}' > INTERVAL '{$clipLength}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)) {
+                    //"Fade In can't be larger than overall playlength.";
+                    $fadeIn = $clipLength;
+                }
+                $row->setDbFadein($fadeIn);
+            }
+            if (!is_null($fadeOut)){
+
+    			$sql = "SELECT INTERVAL '{$fadeOut}' > INTERVAL '{$clipLength}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)) {
+                    //Fade Out can't be larger than overall playlength.";
+                    $fadeOut = $clipLength;
+                }
+                $row->setDbFadeout($fadeOut);
+            }
+
+            $row->save($this->con);
+            $this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
+            $this->pl->save($this->con);
+
+            $this->con->commit();
         }
         catch (Exception $e) {
-            Logging::log($e->getMessage());
+            $this->con->rollback();
+            throw $e;
         }
 
-        return array("fadeIn"=>$fadeIn, "fadeOut"=>$fadeOut);
+        return array("fadeIn"=> $fadeIn, "fadeOut"=> $fadeOut);
     }
 
     public function setPlaylistfades($fadein, $fadeout) {
@@ -512,7 +522,7 @@ class Application_Model_Playlist {
             $row = CcPlaylistcontentsQuery::create()
                 ->filterByDbPlaylistId($this->id)
                 ->filterByDbPosition(0)
-                ->findOne();
+                ->findOne($this->con);
 
             $this->changeFadeInfo($row->getDbId(), $fadein, null);
         }
@@ -521,7 +531,7 @@ class Application_Model_Playlist {
             $row = CcPlaylistcontentsQuery::create()
                 ->filterByDbPlaylistId($this->id)
                 ->filterByDbPosition($this->getSize()-1)
-                ->findOne();
+                ->findOne($this->con);
 
             $this->changeFadeInfo($row->getDbId(), null, $fadeout);
         }
@@ -540,126 +550,135 @@ class Application_Model_Playlist {
      */
     public function changeClipLength($id, $cueIn, $cueOut)
     {
+        $this->con->beginTransaction();
+
         $errArray= array();
-		$con = Propel::getConnection(CcPlaylistPeer::DATABASE_NAME);
 
-        if (is_null($cueIn) && is_null($cueOut)) {
-            $errArray["error"]="Cue in and cue out are null.";
-            return $errArray;
-        }
-
-        $row = CcPlaylistcontentsQuery::create()
-            ->joinWith(CcFilesPeer::OM_CLASS)
-            ->filterByPrimaryKey($id)
-            ->findOne();
-
-        if (is_null($row)) {
-            $errArray["error"]="Playlist item does not exist!.";
-            return $errArray;
-        }
-
-        $oldCueIn = $row->getDBCuein();
-        $oldCueOut = $row->getDbCueout();
-        $fadeIn = $row->getDbFadein();
-        $fadeOut = $row->getDbFadeout();
-
-        $file = $row->getCcFiles();
-        $origLength = $file->getDbLength();
-
-
-        if(!is_null($cueIn) && !is_null($cueOut)){
-
-            if($cueOut === ""){
-                $cueOut = $origLength;
-            }
-
-			$sql = "SELECT INTERVAL '{$cueIn}' > INTERVAL '{$cueOut}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)) {
-                $errArray["error"]= "Can't set cue in to be larger than cue out.";
+        try {
+            if (is_null($cueIn) && is_null($cueOut)) {
+                $errArray["error"] = "Cue in and cue out are null.";
                 return $errArray;
             }
 
-			$sql = "SELECT INTERVAL '{$cueOut}' > INTERVAL '{$origLength}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)){
-                $errArray["error"] = "Can't set cue out to be greater than file length.";
-                return $errArray;
+            $row = CcPlaylistcontentsQuery::create()
+                ->joinWith(CcFilesPeer::OM_CLASS)
+                ->filterByPrimaryKey($id)
+                ->findOne($this->con);
+
+            if (is_null($row)) {
+                throw new Exception("Playlist item does not exist.");
             }
 
-			$sql = "SELECT INTERVAL '{$cueOut}' - INTERVAL '{$cueIn}'";
-			$r = $con->query($sql);
-			$cliplength = $r->fetchColumn(0);
+            $oldCueIn = $row->getDBCuein();
+            $oldCueOut = $row->getDbCueout();
+            $fadeIn = $row->getDbFadein();
+            $fadeOut = $row->getDbFadeout();
 
-            $row->setDbCuein($cueIn);
-            $row->setDbCueout($cueOut);
-            $row->setDBCliplength($cliplength);
+            $file = $row->getCcFiles($this->con);
+            $origLength = $file->getDbLength();
 
-        }
-        else if(!is_null($cueIn)) {
+            if (!is_null($cueIn) && !is_null($cueOut)){
 
-			$sql = "SELECT INTERVAL '{$cueIn}' > INTERVAL '{$oldCueOut}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)) {
-                $errArray["error"] = "Can't set cue in to be larger than cue out.";
-                return $errArray;
+                if ($cueOut === ""){
+                    $cueOut = $origLength;
+                }
+
+    			$sql = "SELECT INTERVAL '{$cueIn}' > INTERVAL '{$cueOut}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)) {
+                    $errArray["error"] = "Can't set cue in to be larger than cue out.";
+                    return $errArray;
+                }
+
+    			$sql = "SELECT INTERVAL '{$cueOut}' > INTERVAL '{$origLength}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)){
+                    $errArray["error"] = "Can't set cue out to be greater than file length.";
+                    return $errArray;
+                }
+
+    			$sql = "SELECT INTERVAL '{$cueOut}' - INTERVAL '{$cueIn}'";
+    			$r = $this->con->query($sql);
+    			$cliplength = $r->fetchColumn(0);
+
+                $row->setDbCuein($cueIn);
+                $row->setDbCueout($cueOut);
+                $row->setDBCliplength($cliplength);
+
+            }
+            else if (!is_null($cueIn)) {
+
+    			$sql = "SELECT INTERVAL '{$cueIn}' > INTERVAL '{$oldCueOut}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)) {
+                    $errArray["error"] = "Can't set cue in to be larger than cue out.";
+                    return $errArray;
+                }
+
+                $sql = "SELECT INTERVAL '{$oldCueOut}' - INTERVAL '{$cueIn}'";
+    			$r = $this->con->query($sql);
+    			$cliplength = $r->fetchColumn(0);
+
+                $row->setDbCuein($cueIn);
+                $row->setDBCliplength($cliplength);
+            }
+            else if (!is_null($cueOut)) {
+
+                if ($cueOut === ""){
+                    $cueOut = $origLength;
+                }
+
+    			$sql = "SELECT INTERVAL '{$cueOut}' < INTERVAL '{$oldCueIn}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)) {
+                    $errArray["error"] = "Can't set cue out to be smaller than cue in.";
+                    return $errArray;
+                }
+
+    			$sql = "SELECT INTERVAL '{$cueOut}' > INTERVAL '{$origLength}'";
+    			$r = $this->con->query($sql);
+                if ($r->fetchColumn(0)){
+                    $errArray["error"] = "Can't set cue out to be greater than file length.";
+                    return $errArray;
+                }
+
+                $sql = "SELECT INTERVAL '{$cueOut}' - INTERVAL '{$oldCueIn}'";
+    			$r = $this->con->query($sql);
+    			$cliplength = $r->fetchColumn(0);
+
+                $row->setDbCueout($cueOut);
+                $row->setDBCliplength($cliplength);
             }
 
-            $sql = "SELECT INTERVAL '{$oldCueOut}' - INTERVAL '{$cueIn}'";
-			$r = $con->query($sql);
-			$cliplength = $r->fetchColumn(0);
+            $cliplength = $row->getDbCliplength();
 
-            $row->setDbCuein($cueIn);
-            $row->setDBCliplength($cliplength);
-        }
-        else if(!is_null($cueOut)) {
-
-            if($cueOut === ""){
-                $cueOut = $origLength;
+    		$sql = "SELECT INTERVAL '{$fadeIn}' > INTERVAL '{$cliplength}'";
+    		$r = $this->con->query($sql);
+            if ($r->fetchColumn(0)){
+                $fadeIn = $cliplength;
+                $row->setDbFadein($fadeIn);
             }
 
-			$sql = "SELECT INTERVAL '{$cueOut}' < INTERVAL '{$oldCueIn}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)) {
-                $errArray["error"] ="Can't set cue out to be smaller than cue in.";
-                return $errArray;
+    		$sql = "SELECT INTERVAL '{$fadeOut}' > INTERVAL '{$cliplength}'";
+    		$r = $this->con->query($sql);
+            if ($r->fetchColumn(0)){
+                $fadeOut = $cliplength;
+                $row->setDbFadein($fadeOut);
             }
 
-			$sql = "SELECT INTERVAL '{$cueOut}' > INTERVAL '{$origLength}'";
-			$r = $con->query($sql);
-            if($r->fetchColumn(0)){
-                $errArray["error"] ="Can't set cue out to be greater than file length.";
-                return $errArray;
-            }
+            $row->save($this->con);
+            $this->pl->setDbMtime(new DateTime("now", new DateTimeZone("UTC")));
+            $this->pl->save($this->con);
 
-            $sql = "SELECT INTERVAL '{$cueOut}' - INTERVAL '{$oldCueIn}'";
-			$r = $con->query($sql);
-			$cliplength = $r->fetchColumn(0);
-
-            $row->setDbCueout($cueOut);
-            $row->setDBCliplength($cliplength);
+            $this->con->commit();
+        }
+        catch (Exception $e) {
+            $this->con->rollback();
+            throw $e;
         }
 
-        $cliplength = $row->getDbCliplength();
-
-		$sql = "SELECT INTERVAL '{$fadeIn}' > INTERVAL '{$cliplength}'";
-		$r = $con->query($sql);
-        if($r->fetchColumn(0)){
-            $fadeIn = $cliplength;
-            $row->setDbFadein($fadeIn);
-        }
-
-		$sql = "SELECT INTERVAL '{$fadeOut}' > INTERVAL '{$cliplength}'";
-		$r = $con->query($sql);
-        if($r->fetchColumn(0)){
-            $fadeOut = $cliplength;
-            $row->setDbFadein($fadeOut);
-        }
-
-        $row->save();
-
-        return array("cliplength"=>$cliplength, "cueIn"=>$cueIn, "cueOut"=>$cueOut, "length"=>$this->getLength(),
-                        "fadeIn"=>$fadeIn, "fadeOut"=>$fadeOut);
+        return array("cliplength"=> $cliplength, "cueIn"=> $cueIn, "cueOut"=> $cueOut, "length"=> $this->getLength(),
+                        "fadeIn"=> $fadeIn, "fadeOut"=> $fadeOut);
     }
 
     public function getAllPLMetaData()
diff --git a/airtime_mvc/public/js/airtime/library/spl.js b/airtime_mvc/public/js/airtime/library/spl.js
index b58a2d87e..5977712dc 100644
--- a/airtime_mvc/public/js/airtime/library/spl.js
+++ b/airtime_mvc/public/js/airtime/library/spl.js
@@ -19,6 +19,10 @@ var AIRTIME = (function(AIRTIME){
         return regExpr.test(fade);
 	}
 	
+	function playlistError(json) {
+		alert(json.error);
+		openPlaylist(json);
+	}
 	
 	function stopAudioPreview() {
 		// stop any preview playing
@@ -51,130 +55,151 @@ var AIRTIME = (function(AIRTIME){
 	function changeCueIn(event) {
 	    event.stopPropagation();
 
-		var id, url, cueIn, li, unqid;
+		var span = $(this),
+			id = span.parent().attr("id").split("_").pop(),
+			url = "/Playlist/set-cue",
+			cueIn = $.trim(span.text()),
+			li = span.parents("li"),
+			unqid = li.attr("unqid"),
+			lastMod = getModified();
 
-		span = $(this);
-		id = span.parent().attr("id").split("_").pop();
-		url = "/Playlist/set-cue";
-		cueIn = $.trim(span.text());
-		li = span.parent().parent().parent().parent();
-		unqid = li.attr("unqid");
-
-		if(!isTimeValid(cueIn)){
+		if (!isTimeValid(cueIn)){
 	        showError(span, "please put in a time '00:00:00 (.000000)'");
 	        return;
 		}
 
-		$.post(url, {format: "json", cueIn: cueIn, id: id, type: event.type}, function(json){
+		$.post(url, 
+			{format: "json", cueIn: cueIn, id: id, modified: lastMod}, 
+			function(json){
 		   
-	        if(json.response !== undefined && json.response.error) {
-	            showError(span, json.response.error);
-				return;
-			}
-	        
-	        setPlaylistContent(json);
-	        
-	        li = $('#side_playlist li[unqid='+unqid+']');
-	        li.find(".cue-edit").toggle();
-	    	highlightActive(li);
-	    	highlightActive(li.find('.spl_cue'));
-		});
+				if (json.error !== undefined){
+	            	playlistError(json);
+	            	return;
+                }
+		        if (json.cue_error !== undefined) {
+		            showError(span, json.cue_error);
+					return;
+				}
+		        
+		        setPlaylistContent(json);
+		        
+		        li = $('#side_playlist li[unqid='+unqid+']');
+		        li.find(".cue-edit").toggle();
+		    	highlightActive(li);
+		    	highlightActive(li.find('.spl_cue'));
+			});
 	}
 
 	function changeCueOut(event) {
 	    event.stopPropagation();
 
-		var id, url, cueOut, li, unqid;
+		var span = $(this),
+			id = span.parent().attr("id").split("_").pop(),
+			url = "/Playlist/set-cue",
+			cueOut = $.trim(span.text()),
+			li = span.parents("li"),
+			unqid = li.attr("unqid"),
+			lastMod = getModified();
 
-		span = $(this);
-		id = span.parent().attr("id").split("_").pop();
-		url = "/Playlist/set-cue";
-		cueOut = $.trim(span.text());
-		li = span.parent().parent().parent().parent();
-		unqid = li.attr("unqid");
-
-		if(!isTimeValid(cueOut)){
+		if (!isTimeValid(cueOut)){
 	        showError(span, "please put in a time '00:00:00 (.000000)'");
 			return;
 		}
 
-		$.post(url, {format: "json", cueOut: cueOut, id: id}, function(json){
+		$.post(url, 
+			{format: "json", cueOut: cueOut, id: id, modified: lastMod}, 
+			function(json){
 		   
-			if(json.response !== undefined && json.response.error) {
-	            showError(span, json.response.error);
-				return;
-			}
-
-			setPlaylistContent(json);
-	        
-	        li = $('#side_playlist li[unqid='+unqid+']');
-	        li.find(".cue-edit").toggle();
-	    	highlightActive(li);
-	    	highlightActive(li.find('.spl_cue'));
-		});
+				if (json.error !== undefined){
+	            	playlistError(json);
+	            	return;
+                }
+				if (json.cue_error !== undefined) {
+		            showError(span, json.cue_error);
+					return;
+				}
+	
+				setPlaylistContent(json);
+		        
+		        li = $('#side_playlist li[unqid='+unqid+']');
+		        li.find(".cue-edit").toggle();
+		    	highlightActive(li);
+		    	highlightActive(li.find('.spl_cue'));
+			});
 	}
 
 	function changeFadeIn(event) {
 	    event.stopPropagation();
 
-		var id, url, fadeIn, li, unqid;
+		var span = $(this),
+			id = span.parent().attr("id").split("_").pop(),
+			url = "/Playlist/set-fade",
+			fadeIn = $.trim(span.text()),
+			li = span.parents("li"),
+			unqid = li.attr("unqid"),
+			lastMod = getModified();
 
-		span = $(this);
-		id = span.parent().attr("id").split("_").pop();
-		url = "/Playlist/set-fade";
-		fadeIn = $.trim(span.text());
-		li = span.parent().parent().parent().parent();
-		unqid = li.attr("unqid");
-
-		if(!isFadeValid(fadeIn)){
+		if (!isFadeValid(fadeIn)){
 	        showError(span, "please put in a time in seconds '00 (.000000)'");
 			return;
 		}
 
-		$.post(url, {format: "json", fadeIn: fadeIn, id: id}, function(json){
+		$.post(url, 
+			{format: "json", fadeIn: fadeIn, id: id, modified: lastMod}, 
+			function(json){
 			
-			if(json.response !== undefined && json.response.error) {
-	            showError(span, json.response.error);
-				return;
-			}
-
-			setPlaylistContent(json);
-	        
-	        li = $('#side_playlist li[unqid='+unqid+']');
-	        li.find('.crossfade').toggle();
-	        highlightActive(li.find('.spl_fade_control'));
-		});
+				if (json.error !== undefined){
+	            	playlistError(json);
+	            	return;
+                }
+				if (json.fade_error !== undefined) {
+					showError(span, json.fade_error);
+					return;
+				}
+	
+				setPlaylistContent(json);
+		        
+		        li = $('#side_playlist li[unqid='+unqid+']');
+		        li.find('.crossfade').toggle();
+		        highlightActive(li.find('.spl_fade_control'));
+			});
 	}
 
 	function changeFadeOut(event) {
 	    event.stopPropagation();
 
-		var id, url, fadeOut, li, unqid;
+		var span = $(this),
+			id = span.parent().attr("id").split("_").pop(),
+			url = "/Playlist/set-fade",
+			fadeOut = $.trim(span.text()),
+			li = span.parents("li"),
+			unqid = li.attr("unqid"),
+			lastMod = getModified();
 
-		span = $(this);
-		id = span.parent().attr("id").split("_").pop();
-		url = "/Playlist/set-fade";
-		fadeOut = $.trim(span.text());
-		li = span.parent().parent().parent().parent();
-		unqid = li.attr("unqid");
-
-		if(!isFadeValid(fadeOut)){
+		if (!isFadeValid(fadeOut)){
 	        showError(span, "please put in a time in seconds '00 (.000000)'");
 			return;
 		}
 
-		$.post(url, {format: "json", fadeOut: fadeOut, id: id}, function(json){
-			if(json.response !== undefined && json.response.error) {
-	            showError(span, json.response.error);
-				return;
-			}
-
-			setPlaylistContent(json);
-	        
-	        li = $('#side_playlist li[unqid='+unqid+']');
-	        li.find('.crossfade').toggle();
-	        highlightActive(li.find('.spl_fade_control'));
-		});
+		$.post(url, 
+			{format: "json", fadeOut: fadeOut, id: id, modified: lastMod}, 
+			function(json){
+			
+				if (json.error !== undefined){
+	            	playlistError(json);
+	            	return;
+                }
+				if (json.fade_error !== undefined) {
+		            showError(span, json.fade_error);
+					return;
+				}
+	
+				setPlaylistContent(json);
+		        
+		        li = $('#side_playlist li[unqid='+unqid+']');
+		        li.find('.crossfade').toggle();
+		        highlightActive(li.find('.spl_fade_control'));
+			});
 	}
 
 	function submitOnEnter(event) {
@@ -221,27 +246,33 @@ var AIRTIME = (function(AIRTIME){
 	}
 
 	function editName() {
-	    var nameElement = $(this);
-	    var playlistName = nameElement.text();
+	    var nameElement = $(this),
+	    	playlistName = nameElement.text(),
+	    	lastMod = getModified();
 
 	    $("#playlist_name_input")
 	        .removeClass('element_hidden')
 	        .val(playlistName)
 	        .keydown(function(event){
-	        	if(event.keyCode === 13) {
+	        	if (event.keyCode === 13) {
 	                event.preventDefault();
-	                var input = $(this);
-	                var url;
-	    	        url = '/Playlist/set-playlist-name';
+	                var input = $(this),
+	    	        	url = '/Playlist/set-playlist-name';
 
-	    	        $.post(url, {format: "json", name: input.val()}, function(json){
-	    	            if(json.playlist_error == true){
-	    	                alertPlaylistErrorAndReload();
-	    	            }
-	                    input.addClass('element_hidden');
-	                    nameElement.text(json.playlistName);
-	                    redrawLib();
-	    	        });
+	    	        $.post(url, 
+	    	        	{format: "json", name: input.val(), modified: lastMod}, 
+	    	        	function(json){
+	    	        	
+		    	            if (json.error !== undefined) {
+		    	            	playlistError(json);
+		    	            }
+		    	            else {
+		    	            	setModified(json.modified);
+			                    input.addClass('element_hidden');
+			                    nameElement.text(json.playlistName);
+			                    redrawLib();
+		    	            }
+		    	        });
 	        	}
 	        })
 	        .focus();
@@ -269,7 +300,9 @@ var AIRTIME = (function(AIRTIME){
 		$('#spl_sortable')
 			.empty()
 			.append(json.html);
-
+		
+		setModified(json.modified);
+		
 		redrawLib();
 	}
 	
@@ -281,6 +314,10 @@ var AIRTIME = (function(AIRTIME){
 		return parseInt($("#pl_lastMod").val(), 10);
 	}
 	
+	function setModified(modified) {
+		$("#pl_lastMod").val(modified);
+	}
+	
 	function openPlaylist(json) {
 		
 		$("#side_playlist")
@@ -335,9 +372,11 @@ var AIRTIME = (function(AIRTIME){
 	function setUpPlaylist(playlist) {
 		
 		var playlist = $("#side_playlist"),
-			sortableConf;
+			sortableConf,
+			cachedDescription;
 
-	    playlist.find("#spl_crossfade").on("click", function(){
+	    playlist.find("#spl_crossfade").on("click", function() {
+	    	var lastMod = getModified();
 
 	        if ($(this).hasClass("ui-state-active")) {
 	            $(this).removeClass("ui-state-active");
@@ -348,19 +387,23 @@ var AIRTIME = (function(AIRTIME){
 
 	            var url = '/Playlist/get-playlist-fades';
 
-		        $.get(url, {format: "json"}, function(json){
-		            if(json.playlist_error == true){
-	                    alertPlaylistErrorAndReload();
-	                }
-		            playlist.find("#spl_fade_in_main").find("span")
-	                    .empty()
-	                    .append(json.fadeIn);
-		            playlist.find("#spl_fade_out_main").find("span")
-	                    .empty()
-	                    .append(json.fadeOut);
-
-		            playlist.find("#crossfade_main").show();
-	            });
+		        $.get(url, 
+		        	{format: "json", modified: lastMod}, 
+		        	function(json){
+			            if (json.error !== undefined){
+			            	playlistError(json);
+		                }
+			            else {
+				            playlist.find("#spl_fade_in_main").find("span")
+			                    .empty()
+			                    .append(json.fadeIn);
+				            playlist.find("#spl_fade_out_main").find("span")
+			                    .empty()
+			                    .append(json.fadeOut);
+		
+				            playlist.find("#crossfade_main").show();
+			            }
+		            });
 	        }
 	    });
 
@@ -369,7 +412,8 @@ var AIRTIME = (function(AIRTIME){
 		playlist.find("#fieldset-metadate_change > legend").on("click", function(){
 	        var descriptionElement = $(this).parent();
 
-	        if(descriptionElement.hasClass("closed")) {
+	        if (descriptionElement.hasClass("closed")) {
+	        	cachedDescription = playlist.find("#fieldset-metadate_change textarea").val();
 	            descriptionElement.removeClass("closed");
 	        }
 	        else {
@@ -380,77 +424,71 @@ var AIRTIME = (function(AIRTIME){
 		playlist.find("#description_save").on("click", function(){
 	        var textarea = playlist.find("#fieldset-metadate_change textarea"),
 	        	description = textarea.val(),
-	        	url;
+	        	url,
+	        	lastMod = getModified();;
 	        
 	        url = '/Playlist/set-playlist-description';
 
-	        $.post(url, {format: "json", description: description}, function(json){
-	            if(json.playlist_error == true){
-	                alertPlaylistErrorAndReload();
-	            }
-	            else{
-	                textarea.val(json.playlistDescription);
-	            }
-	            
-	            playlist.find("#fieldset-metadate_change").addClass("closed");
-	            redrawLib();
-	        });
+	        $.post(url, 
+        		{format: "json", description: description, modified: lastMod}, 
+        		function(json){
+		            if (json.error !== undefined){
+		            	playlistError(json);
+		            }
+		            else{
+		            	setModified(json.modified);
+		                textarea.val(json.description);
+		                playlist.find("#fieldset-metadate_change").addClass("closed");
+			            redrawLib();
+		            }      
+		        });
 	    });
 
 		playlist.find("#description_cancel").on("click", function(){
-	        var textarea = playlist.find("#fieldset-metadate_change textarea"),
-	        	url;
+	        var textarea = playlist.find("#fieldset-metadate_change textarea");
 	        
-	        url = '/Playlist/set-playlist-description';
-
-	        $.post(url, {format: "json"}, function(json){
-	            if(json.playlist_error == true){
-	                alertPlaylistErrorAndReload();
-	            }
-	            else{
-	                textarea.val(json.playlistDescription);
-	            }
-	            
-	            playlist.find("#fieldset-metadate_change").addClass("closed");
-	        });
+	        textarea.val(cachedDescription);   
+	        playlist.find("#fieldset-metadate_change").addClass("closed");
 	    });
 
 		playlist.find("#spl_fade_in_main span:first").on("blur", function(event){
 	        event.stopPropagation();
 
-		    var url, fadeIn, span;
-		    span = $(this);
-		    url = "/Playlist/set-playlist-fades";
-		    fadeIn = $.trim(span.text());
-
-		    if(!isFadeValid(fadeIn)){
+		    var url = "/Playlist/set-playlist-fades",
+			    span = $(this),
+			    fadeIn = $.trim(span.text()), 
+			    lastMod = getModified();
+		    
+		    if (!isFadeValid(fadeIn)){
 	            showError(span, "please put in a time in seconds '00 (.000000)'");
 			    return;
 		    }
 
-		    $.post(url, {format: "json", fadeIn: fadeIn}, function(json){
-		        
-	            hideError(span);
-		    });
+		    $.post(url, 
+	    		{format: "json", fadeIn: fadeIn, modified: lastMod}, 
+	    		function(json){       
+		            hideError(span);
+			    });
 	    });
 
 		playlist.find("#spl_fade_out_main span:last").on("blur", function(event){
 	        event.stopPropagation();
 
-		    var url, fadeOut, span;
-
-		    span = $(this);
-		    url = "/Playlist/set-playlist-fades";
-		    fadeOut = $.trim(span.text());
+		    var url = "/Playlist/set-playlist-fades",
+		    	span = $(this),
+		    	fadeOut = $.trim(span.text()), 
+		    	lastMod = getModified();
 
 		    if(!isFadeValid(fadeOut)){
 	            showError(span, "please put in a time in seconds '00 (.000000)'");
 			    return;
 		    }
 
-		    $.post(url, {format: "json", fadeOut: fadeOut}, function(json){
-	            hideError(span);
-		    });
+		    $.post(url, 
+		    	{format: "json", fadeOut: fadeOut, modified: lastMod}, 
+		    	function(json){
+		            hideError(span);
+			    });
 	    });
 
 		playlist.find("#spl_fade_in_main span:first, #spl_fade_out_main span:first")
@@ -501,7 +539,7 @@ var AIRTIME = (function(AIRTIME){
 			
 			return {
 				items: 'li',
-				placeholder: "placeholder lib-placeholder ui-state-highlight",
+				placeholder: "placeholder ui-state-highlight",
 				forcePlaceholderSize: true,
 				handle: 'div.list-item-container',
 				start: function(event, ui) {
@@ -518,30 +556,28 @@ var AIRTIME = (function(AIRTIME){
 	}
 	
 	mod.fnNew = function() {
-		var url;
+		var url = '/Playlist/new';
 
 		stopAudioPreview();
-		url = '/Playlist/new';
-
-		$.post(url, {format: "json"}, function(json){
-			openPlaylist(json);
-			redrawLib();
-		});
+		
+		$.post(url, 
+			{format: "json"}, 
+			function(json){
+				openPlaylist(json);
+				redrawLib();
+			});
 	};
 	
 	mod.fnEdit = function(id) {
-		var url;
+		var url = '/Playlist/edit';;
 		
 		stopAudioPreview();	
 		
-		url = '/Playlist/edit';
-
 		$.post(url, 
 			{format: "json", id: id}, 
 			function(json){
 				openPlaylist(json);
-				//redrawLib();
-		});
+			});
 	};
 	
 	mod.fnDelete = function(plid) {
@@ -557,33 +593,51 @@ var AIRTIME = (function(AIRTIME){
 			function(json){
 				openPlaylist(json);
 				redrawLib();
-		});
+			});
 	};
 	
 	mod.fnAddItems = function(aItems, iAfter, sAddType) {
+		var lastMod = getModified();
 		
 		$.post("/playlist/add-items", 
-			{format: "json", "ids": aItems, "afterItem": iAfter, "type": sAddType}, 
+			{format: "json", "ids": aItems, "afterItem": iAfter, "type": sAddType, "modified": lastMod}, 
 			function(json){
-				setPlaylistContent(json);
+				if (json.error !== undefined) {
+					playlistError(json);
+				}
+				else {
+					setPlaylistContent(json);
+				}
 			});
 	};
 	
 	mod.fnMoveItems = function(aIds, iAfter) {
+		var lastMod = getModified();
 		
 		$.post("/playlist/move-items", 
-			{format: "json", "ids": aIds, "afterItem": iAfter}, 
+			{format: "json", "ids": aIds, "afterItem": iAfter, "modified": lastMod}, 
 			function(json){
-				setPlaylistContent(json);
+				if (json.error !== undefined) {
+					playlistError(json);
+				}
+				else {
+					setPlaylistContent(json);
+				}
 			});
 	};
 	
 	mod.fnDeleteItems = function(aItems) {
+		var lastMod = getModified();
 		
 		$.post("/playlist/delete-items", 
-			{format: "json", "ids": aItems}, 
+			{format: "json", "ids": aItems, "modified": lastMod}, 
 			function(json){
-				setPlaylistContent(json);
+				if (json.error !== undefined) {
+					playlistError(json);
+				}
+				else {
+					setPlaylistContent(json);
+				}
 			});
 	};