Xml not loading after preloader

My xml was loading fine until I made a preloader( not made, did it with a tuto).
The preloader is on frame 1 and the xml + all items on my stage are on frame 3.
I traced the xml but it comes out undefined…
What is happening ??Do I miss something else to launch my xml loading ?
Here is the code for the preloader in case :
stop();
this.onEnterFrame = function() {
var amount:Number = this.getBytesLoaded()/this.getBytesTotal()*100;
loader._xscale = amount;
if (amount == 100) {
this.gotoAndPlay(3);
delete this.onEnterFrame;
}
};
Thank you for your opinions!