Movie in a movie

First, I am new to flash and actionscript.

I have a movie clip (movieA_mc) that I attach (using attachMovie) to the main movie. This movie moves when I move the mouse over it. I then attach (using attachMovie) another movie (movieB_mc) to movieA_mc. movieB_mc has a button in it.

When I movie the mouse over movieA_mc it works fine, but when I put the mouse over movieB_mc, movieA_mc stops moving.

Sorry if I didnt explain this to well, and sorry for not attaching the script, but it is at home.

Thanks