Loading External Swf into Movie Clip ... Preloader Problem

Hi,

i don`t know how i got back to the basics but i am having a problem with a preloader.
What i do…
I have an empty movie clip that loads an swf after a user make a button choise.
So after the user choise i make the preloader._visible = true;
and in the preloaders movie clip i have this code

onClipEvent (enterFrame) {
_root.externals.stop();
mctotal = _root.externals.getBytesTotal();
mcloaded = _root.externals.getBytesLoaded();
percent = Math.round((mcloaded/mctotal)*100);
load = percent+"%";
if (percent == 100) {
_root.externals.play();
this._parent._visible = false;
}
}

The **"_root.externals" **is the empty movie clip that loads the external swf.
The problem is that when the preloader goes to 100% the external swf plays but plays in loop all the time.
In the external swf i have the action stop(); in a frame but it doesn`t stop
insted of stoping it replays all the time…

Any idea what can i do???