     private function set hsbVisible(value:Boolean):void
     {
         var hsb:ScrollBarBase = getScroller().horizontalScrollBar;
-        if (!hsb)
+        if (!hsb || hsb.visible == value)
             return;
 
         hsb.includeInLayout = hsb.visible = value;

    private function set vsbVisible(value:Boolean):void
    {
        var vsb:ScrollBarBase = getScroller().verticalScrollBar;
        if (!vsb)
            return;
        
        vsb.includeInLayout = vsb.visible = value;

                hsbScaleY = hsb.scaleY;
            hsb.scaleX = hsb.scaleY = 0;            
        }
        
        // TODO (rfrishbe) (or hmuller): perhaps rather than setting scale to 0,
        // we should be adding/removing it from the display list
    }

    /**
