Animated Buttons

Okay here is a link to what i am kinda about to describe:

http://www.kirupa.com/developer/flash5/animatedrollover.htm

i used to be able to easily do this in previous versions of flash, but for some reason, i have flash pro 2004 now, when i insert a movie clip into the “over” keyframe of a button i get no motion when i go over the button while testing it, does anybody know why this won’t work so simply? or am i just crazy?