MOUSE_DOWN issue

Hi All,
I was wondering if anyone could help me…
I have the following game:
dev.multimedi8.com
I assign the following event listener at the top of frame 1:

crossHair.addEventListener(MouseEvent.MOUSE_DOWN, shoot);

But it doesn’t trigger on every MOUSE_DOWN. Does anyone have any ideas what could be causing the problem? I mean it should at least get called on every mouse press right?

Forgot to mention all the germ movieclips are created inside a holding movieclip:

mc.addChild(germ)

Thanks for your time