Code can't keep up with mouse

Thanks for your help and patience kglad, I'm having trouble finding more information to try to solve this problem..

onEnterFrame = function() {
if(menu_mc.hitTest(_xmouse, _ymouse, false)) {
menu_mc._yscale = 600;
trace("true");
}
else {
menu_mc._yscale = 100;
trace("false");
}
}

This is the simplest piece of code I could think of based on your advice and it suffers from the exact same problem - mouse out too quickly and the menu stays in the open position. I think the problem is that hitTest isn't actually returning as false here, the 'if' statement is.. does that sound correct?

using onEnterFrame has nothing to do with the number of frames in your swf. in particular, a one frame swf will execute an onEnterFrame loop without issue.

and yes, that's the point: an onEnterFrame loop or setInterval loop continue to execute no matter the location of the mouse and using a hitTest will be accurate no matter the location of the mouse. both of those are problems (mouse location and detecting mouse movement) with your code.

set up your conditional to check for a negative or positive hitTest and use a setInterval() or onEnterFrame loop.