Movie clip doesn't respond to gotoAndPlay()

programming flash
1

My movie clip doesn’t respond to gotoAndPlay(1) command at all. Here is the situation:
The Main.fla has a movie clip instance “Mov1” and the following AS3 code in the first timeframe:

function LoadSWF(Mov:Object, swf:String ):void {
fl_Loader = new Loader();
fl_Loader.load(new URLRequest(swf));
Mov.addChild(fl_Loader);
}
LoadSWF(Mov1, “ChildMovie_1.swf”);

Once it’s loaded it plays once (there is a stop(); at the end).
So far so good but… the following code in the button script doesn’t trigger any action at all:

Mov1.gotoAndPlay(1);

Any other code in that button works fine, so the button itself works ok.
Anyone know what am I missing? Any “import” piece?
Thanks a lot in advance…