I have a Logitech Optical wheel mouse (USB), and the LED blinks all the time (maybe not all the time, but a lot of the time) without me touching it. It either blinks bright/dim, bright/dim, or it just stays bright like I'm moving it, until I move it again to make it stop. Those of you with an Optical mouse should know what I'm talking about. So what the heck? It's getting pretty damn annoying.