Hmm, well, I have the mouse connected to the PS2 port via the PS2 converter. Maybe I'll try plugging in to the USB port. Basically, I replaced my older Mouseman with the Optical Mouseman and didn't bother installing new drivers (call it a case of laziness). And yes, I'm sure the computer is off. Hmm, now that I think about it, I have had problems with one of my keyboard lights staying on with the power off. Must be my Abit MB...