I just realized my Zapper isn't working with my HDTV flat monitor. This is the first time I've tried to use a Zapper with my HDTV and I had no idea that it wouldn't function right on it. I thought maybe the Zapper was screwed up, so I hooked up the NES to an old 21 inch conventional tv set and it worked perfect.
Anyone know the technical aspects of why a Zapper won't work on a flat screen? I would imagine it has something to do with the lens on the zapper being curved.