diff --git a/chrome/content/zotero/xpcom/data_access.js b/chrome/content/zotero/xpcom/data_access.js
index 984d47d16..6e84e3208 100644
--- a/chrome/content/zotero/xpcom/data_access.js
+++ b/chrome/content/zotero/xpcom/data_access.js
@@ -2205,7 +2205,7 @@ Zotero.Item.prototype.erase = function(deleteChildren){
 	Zotero.debug('Deleting item ' + this.getID());
 	
 	var changedItems = [];
-	changedItemsNotifierData = {};
+	var changedItemsNotifierData = {};
 	
 	Zotero.DB.beginTransaction();
 	
diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index 79338412b..563810033 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -80,6 +80,8 @@ var Zotero = new function(){
 	var _zoteroDirectory = false;
 	var _debugLogging;
 	var _debugLevel;
+	var _debugTime;
+	var _debugLastTime;
 	//var _shutdown = false;
 	var _localizedStringBundle;
 	
@@ -108,6 +110,7 @@ var Zotero = new function(){
 		
 		_debugLogging = Zotero.Prefs.get('debug.log');
 		_debugLevel = Zotero.Prefs.get('debug.level');
+		_debugTime = Zotero.Prefs.get('debug.time');
 		
 		// Load in the extension version from the extension manager
 		var nsIUpdateItem = Components.interfaces.nsIUpdateItem;
@@ -429,7 +432,23 @@ var Zotero = new function(){
 			return false;
 		}
 		
-		dump('zotero(' + level + '): ' + message + "\n\n");
+		var deltaStr = '';
+		if (_debugTime) {
+			var delta = 0;
+			var d = new Date();
+			if (_debugLastTime) {
+				delta = d - _debugLastTime;
+			}
+			_debugLastTime = d;
+			
+			while (("" + delta).length < 7) {
+				delta = '0' + delta;
+			}
+			
+			deltaStr = '(+' + delta + ')';
+		}
+		
+		dump('zotero(' + level + ')' + deltaStr + ': ' + message + "\n\n");
 		return true;
 	}
 	
diff --git a/defaults/preferences/zotero.js b/defaults/preferences/zotero.js
index 22536256a..ad1c3b7aa 100644
--- a/defaults/preferences/zotero.js
+++ b/defaults/preferences/zotero.js
@@ -7,6 +7,7 @@ pref("extensions.zotero.dataDir", '');
 pref("extensions.zotero.lastDataDir", '');
 pref("extensions.zotero.debug.log",false);
 pref("extensions.zotero.debug.level",5);
+pref("extensions.zotero.debug.time", false);
 pref("extensions.zotero.automaticScraperUpdates",true);
 pref("extensions.zotero.cacheTranslatorData",true);
 pref("extensions.zotero.zoteroPaneOnTop",false);