     /**
      *  @inheritDoc
      */
-    public function getHorizontalScrollPositionDelta(unit:ScrollUnit):Number
+    public function getHorizontalScrollPositionDelta(scrollUnit:uint):Number
     {
         return (dataGroup) ? 
-            dataGroup.getHorizontalScrollPositionDelta(unit) : 0;     
-    }
-    
-    /**
-     *  @inheritDoc
-     */
-    public function getVerticalScrollPositionDelta(unit:ScrollUnit):Number
+            dataGroup.getHorizontalScrollPositionDelta(scrollUnit) : 0;     
+    }
+    
+    /**
+     *  @inheritDoc
+     */
+    public function getVerticalScrollPositionDelta(scrollUnit:uint):Number
     {
         return (dataGroup) ? 
-            dataGroup.getVerticalScrollPositionDelta(unit) : 0;     
+            dataGroup.getVerticalScrollPositionDelta(scrollUnit) : 0;     
     }
 
     //--------------------------------------------------------------------------

            
            dataGroupProperties = newDataGroupProperties;
            
            dataGroup.addEventListener(
                ItemExistenceChangedEvent.ITEM_ADD, dataGroup_itemAddedHandler);
            dataGroup.addEventListener(
                ItemExistenceChangedEvent.ITEM_REMOVE, dataGroup_itemRemovedHandler);
            dataGroup.addEventListener(
                PropertyChangeEvent.PROPERTY_CHANGE, dataGroup_propertyChangeHandler);
        }

    //
    //--------------------------------------------------------------------------
    
   /**
    * @private
    */
