Roll Over: How to play a movieclip without skipping

Ok here is my problem. To make it easy to understand I will use a simple example.

I want it the roll over of my button to play a ball bouncing. But the problem that I am having is when i rollover the button, and then roll back over the button quickly, it glitches the animation.

Does anyone know how to fix this with an If/Then statement? Like make the rollover only activate when the Ball movieclip is only on Frame 1?

Thanks
Mike