hrm.. still cant come up with anything on taht mouse.

i am leaning towards saying that the mouse is defective and/or the cause of the problem. i dont know how much you want want to hear this, but i would try returning that mouse or something along those lines.

or better yet, find a friend with a USB mouse and have him/her bring it over and try it on your PC.

but still.. considering all your other USB devices work.. i still think it is a problem with that mouse.