      */
     mx_internal function findItem(values:Object, mode:String, insertIndex:Boolean = false):int
     {
-        if (!sort)
+        if (!sort || !localIndex)
         {
             var message:String = resourceManager.getString(
                 "collections", "itemNotFound");


            return -1;
        }
        else if (filterFunction != null)
        {
            var len:int = localIndex.length;
            for (i = 0; i < len; i++)

    {
        var i:int;
        
        if (localIndex && sort)
        {
            var startIndex:int = sort.findItem(localIndex, item, Sort.FIRST_INDEX_MODE);
            if (startIndex == -1)
