I've noticed a weird problem with my NEC avenue controller and using it on my Duo with a multitap, hitting I and up seems to trigger button 2 and some other weird things eventually causing a pause, this made it a real problem playing Bonk (and going up a waterfall). When I plug the controller directly into the Duo its fine, when I use a normal 2 button Duo pad with while using the tap it's fine. So it's not the controller, it's not the tap, I'm guessing there's some sort of a compatibility issue. And I am using a Japanese PCE tap with my Duo.