[flexcoders] Help with Binding

[rss181919]

In the following code, the localProductId binding fails. Why? 
The 1st alert pops with a new value for the variable (indicating that 
it is changing). But the second alert never pops. 
Attach Code 

[Bindable] public var localProductsAC:ArrayCollection = new 
ArrayCollection;
[Bindable] public var localVersionsAC:ArrayCollection = new 
ArrayCollection;
[Bindable] public var localReleasesAC:ArrayCollection = new 
ArrayCollection;
[Bindable] public var localProductId:uint;
[Bindable] public var localVersionId:uint;
        
public function myCreationComplete():void
{
   //bind local products AC to VML source
   BindingUtils.bindSetter(productResult, PrdVML.getInstance
(), "sourcePrdVOList");
   //bind version refresh to product id change
   BindingUtils.bindSetter(versionRefresh, this, "localProductId");
   //bind local versions AC to VML source
   BindingUtils.bindSetter(versionResult, VrsVML.getInstance
(), "sourceVrsVOList");
   productRefresh();
}

public function productRefresh():void
{
   //fetch the list of products
   var outEvent:CairngormEvent  = new CairngormEvent
(PrdController.FETCH_ALL);
   CairngormEventDispatcher.getInstance().dispatchEvent(outEvent);
}

public function productResult(value:ArrayCollection):void
{
   localProductsAC = value;
   localProductId = value.getItemAt(0).PrdId;
   Alert.show(String(localProductId));  
}

public function versionRefresh(value:uint):void 
{
   //fetch versions
  Alert.show('hit');
   var fetchVersionsEvent:MyEvent = new MyEvent
(VrsController.FETCH_FOR_PRODUCT);
   fetchVersionsEvent.eventObject = {PrdId:localProductId};
   CairngormEventDispatcher.getInstance().dispatchEvent
(fetchVersionsEvent);
}