codice:
onClipEvent (load) {
	_visible = false;
	_root.stop();
}
onClipEvent (enterFrame) {
	if (_root.getBytesLoaded() == _root.getBytesTotal()) {
		_root.nextFrame();
	}
	_visible = false;
	perc = barra._xscale=Math.round((_root.getBytesLoaded()/_root.getBytesTotal())*100);
	percentuale = perc+"%";
}
Bisogna usare, per la proprietà _visible, solo "true" e "false"..