Ok vedi se così ti va bene
codice:
stop()
preload.barra._width=0

_level0.onEnterFrame=function(){
        car=this.getBytesLoaded()
        tot=this.getBytesTotal()
        perc=Math.round(car/tot*100)
		
		X=340 - preload.barra._width
		preload.barra._width+=X/perc        
        if(car==tot && car >1024){
          // caricamento avvenuto
             preload.barra._alpha=100
             preload.barra.onEnterFrame=function(){
                if(this._alpha>0){this._alpha-=10}
                else{delete this.onEnterFrame}
             }
             delete this.onEnterFrame
        }
}