diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 80f96a51b5..6193d67c0c 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -1763,7 +1763,7 @@ Zotero.Item.prototype.save = function() {
 				if (this._previousData) {
 					var oldSourceItemKey = this._previousData.sourceItemKey;
 					if (oldSourceItemKey) {
-						var oldSourceItem = Zotero.Items.getByKey(this.libraryID, oldSourceItemKey);
+						var oldSourceItem = Zotero.Items.getByLibraryAndKey(this.libraryID, oldSourceItemKey);
 					}
 					if (oldSourceItem) {
 						var oldSourceItemNotifierData = {};
diff --git a/chrome/content/zotero/xpcom/sync.js b/chrome/content/zotero/xpcom/sync.js
index 870145cabc..583f41dfde 100644
--- a/chrome/content/zotero/xpcom/sync.js
+++ b/chrome/content/zotero/xpcom/sync.js
@@ -1720,6 +1720,15 @@ Zotero.Sync.Server = new function () {
 		
 		Zotero.Sync.Runner.setError(e.message ? e.message : e);
 		Zotero.Sync.Runner.reset();
+		try {
+			undefinedFunction();
+		}
+		catch (e) {
+			// Log stack trace to error console
+			if (e.stack) {
+				Components.utils.reportError(e.stack.substr(0, 600));
+			}
+		}
 		Components.utils.reportError(e);
 	}
 }