100% Processor usage need help optimising

I’ve made a basic menu system in which everything moves (including alpha) by using action script, but the problem is that it constantly uses 100% CPU and there is a noticable system slowdown, I’ve tried looking over the code but no luck so far. Can anyone else see what the problem is. (Symbol 14 is the main menu, everything in there has an alpha value of zero to begin with.)

http://www.geocities.com/invisible5uk/bigart.fla
http://www.geocities.com/invisible5uk/bigart.html

Thanks