Hit zones inside a movie button?

Hi

I’ve created a movie button which when you roll over an animated section extends down and when you roll out, it goes back to it’s previous position.

Problem is, because the movie extends so does the hit zone. Ideally I want only the initial button to act as the roll over/roll out trigger and not the extended section that drops down.

So once they roll over the button, they can move the mouse down into this extended area and there is no roll out effect.

So… does anyone know how you can avoid this?

Hope I made sense?

Cheers

Tris