I have the same thing going on. After I shut down, that optical red light is still on. I actually thought it did that until now. I've had it (Microsoft Optical PS2/USB) for about a year, and it's still kickin'! But yeah, I understand you, the mouse was $50...I'd be paranoid too. Don't know what to say though. If you can't find a solution and are still paranoid about it, I suppose you can just unplug it...