ActionScript 3.0 :: Listening For The End Of External Audio Files?

I have an event listener that is listening for the end of an eternal audio file. I want to move to the next page after an external audio file has completed playing: here is the code I have so far:

ActionScript Code:
d1Channel.addEventListener(Event.SOUND_COMPLETE, soundComplete, false, 0, true);
function soundComplete( e:Event ):void {
gotoAndPlay("next_page");
trace("sound over");
}

This seems to work intermittently. Sometimes it will, and other times it won't. Is there anything wrong with my code or theory. Is there a better way to do this that will yield more consistent results? Or do I need to import any Flash Events?