Strange TweenEvent.MOTION_START problem, not dispatching

programming flash
1

I’m having trouble getting the TweenEvent.MOTION_START to work.

This doesn’t work???


public function tweenTest():void{
var t:Tween = new Tween(shape, Tweenables.Y, Elastic.easeOut, 100, 300, 2, true);
            t.addEventListener(TweenEvent.MOTION_START, onTweenEvent);
}

private function onTweenEvent(te:TweenEvent):void{
            trace(te.position);    
}

But this code does work???


public function tweenTest():void{
var t:Tween = new Tween(shape, Tweenables.Y, Elastic.easeOut, 100, 300, 2, true);
            t.addEventListener(TweenEvent.MOTION_STOP, onTweenEvent);
}

private function onTweenEvent(te:TweenEvent):void{
            trace(te.position);    
}

It seems like the start event is just not firing? Has anyone come across this, is there something else I need to do to get the motion start event to dispatch?

Thanks in advance