Sound doesn't play

Hi,

I have a Flash movie that uses the following code to load a Sound from the library:


this.lancet_mc.onRelease = function() {
if (lancet_mc.hitTest(target_mc) == true) {
var my_sound:Sound = new Sound();
my_sound.attachSound("mySoundID");
my_sound.onSoundComplete = function() {
trace("mySoundID completed");
};
my_sound.start();
}

It works fine, but when I load the movie from another movie, the sound does not play.

What am I doing wrong?

Thanks