         if (isOpen)
         {   
             _isOpen = false;
-            openButton.mx_internal::keepDown = false;
+            openButton.keepDown = false;
             
             var dde:DropDownEvent = new DropDownEvent(DropDownEvent.CLOSE, false, true);
             

import mx.events.SandboxMouseEvent;

import spark.events.DropDownEvent; 
 
/**
 *  The DropDownController class handles the mouse, keyboard, and focus
 *  interactions for an anchor button and its associated drop down. 

            addCloseTriggers();
            
            _isOpen = true;
            openButton.keepDown = true; // Force the button to stay in the down state
            
            dispatchEvent(new DropDownEvent(DropDownEvent.OPEN));
        }
