ActionScript 2.0 :: Scripted Tween Then Preload Movieclip?

first frame of my movie i have a stop frame with a simple clip which i tween (tween class) in that same frame. just a white line that comes in and slides down the stage. i'm not preloading this movie itself because it only contains that initial tween and some light actionscript.My tween ends, triggers .onMotionFinished and I load a 1000px x 620px jpeg into a 2nd movie clip and advance to the next frame in the main timeline where I have a 3rd movie clip with a basic preloader bar movie clip inside it.on that 2nd frame i assign an .onEnterFrame function to that 3rd clip like this:

Code:
stop();
preloadClip.onEnterFrame=function(){
bytes_loaded = Math.round(this._parent.picHolder.getBytesLoaded());
bytes_total = Math.round(this._parent.picHolder.getBytesTotal());

[code]....

i usually use .onEnterFrame in this manner to preload stuff into clips with no problems.. for some reason, now my loadBar inside the preload clip gets moved over to the left end of the stage and doesn't appear to register any change in the ._width if i test movie and simulate download.