AS2 | Preloader issues...

[oojustinoo]

Hi everybody, I just realized, that my preloader isn't actually working, and all thanks to trying to load the page on a PC with quite slow internet... The story is following - my preloader animation plays, but only after the whole movie is loaded, cuz I noticed a huge delay before the preloader was actually played... And then I used that flash speed testing thing (sorry, but I don't know how it's called) and it proved my theory...
That's the code on 1-st frame, where preloader is:

stop();
var loaded:Number = getBytesLoaded();
var total:Number = getBytesTotal();
var percent:Number = Math.floor((loaded*100)/total);
if (loaded == total){
gotoAndPlay (2);
}else{
    _preloader.gotoAndPlay(percent);
    //loadBar.percentage.text = percent;
}

And preloader itself has

_parent.gotoAndPlay(2);

on it's frame 100.

Can anybody tell me, where is my mistake?