Problem using btns inside movieclip

Hello.

I’ve built an interactive menu with simple buttons. The buttons are placed within a movieclip which I want to animate when the mouse is over.
The menu is suppose to slide up and down on onmouseover and onmouseout.

I’m using the following AS on my movieclip:

[AS]
on (rollOver) {
_root.mainMenu.menuIns.animUp(0,5);
}
on (rollOut) {
_root.mainMenu.menuIns.animDown(88,5);
}
[/AS]

The functions animUp and animDown are prototypes that I’ve previously declared.

With this code I get a really nice slide effect on my menu but the menu buttons within my movieclip becomes inactive and unable to reach.
Why is that so? and how can I solve this problem?

Regards,