ActionScript 1/2 :: Loaded Movie Does Not Stop In Firefox

I have a main movie which loads a movie with buttons, a button is clicked and movie goes to second frame and plays an animation then at the end of the animation it loads the next movie. ToolShopAnim01.swf does not stop on the first frame. I can not figure out why. Sometimes it works, but I can't seem to find the cause of it not stopping!

Here is the code in that frame once animation stops.
stop();
_parent.startPreload("ToolShopAnim01.swf");

The code below is on the first frame of ToolShopAnim01.swf.
stop();
foundational.onRelease = function() {
gotoAndPlay (2);
} foundational.onRollOver = function() {
[Code] .....