Do you think it could be that it needs a solid hit area? Like for instance, an invisible shape made into a movie clip placed above all the other objects inside the buttons? Happens to me sometimes.
Firsh, email so i can send you a plain fla example using mcs that works perfectly.
Try by disabling the button on Release:
This actually works and doesn’t needs to move cursor. Btw, I would like to see a title “Silly button problem on AS2 ”