I've noticed that with a ButtonBar, the mouse move event does not fire when
moving over the gap between buttons (when there is a horizontal gap). However,
ButtonBar derives from Box which does fire mouse move when moving over the gaps
but I can't see anywhere in the code that changes this behaviour for ButtonBar.
Is there a way for this event to be fired on ButtonBar? Simple example attached.

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical">

<mx:Script>
<![CDATA[
private var i:int = 0;
private function moving():void
{
trace(i++ + " moving");
}

]]>
</mx:Script>

<mx:ButtonBar horizontalGap="20" mouseMove="moving()">
<mx:dataProvider>
<mx:Array>
<mx:String>Flash</mx:String>
<mx:String>Director</mx:String>
<mx:String>Dreamweaver</mx:String>
<mx:String>ColdFusion</mx:String>
</mx:Array>
</mx:dataProvider>
</mx:ButtonBar>


<mx:Box direction="horizontal" mouseMove="moving()" horizontalGap="10">
<mx:Button/>
<mx:Button/>
</mx:Box>

</mx:Application>