--- a/integration/js/metadataplayer-core.js	Thu Jun 06 15:48:09 2013 +0200
+++ b/integration/js/metadataplayer-core.js	Thu Jun 06 16:13:09 2013 +0200
@@ -1180,7 +1180,10 @@
             return (_e.elementType === _listId);
         });
     } else {
-        return this.contents[_listId] || new IriSP.List(this.directory);
+        if (typeof this.contents[_listId] === "undefined") {
+            this.contents[_listId] = new IriSP.List(this.directory);
+        }
+        return this.contents[_listId];
     }
 };