Has anyone had a wireless optical mouse just stop working? I changed the batteries (twice), I tried a different USB port (the computer found the new hardware), reset the receiver and the mouse, and I restarted the computer. The LED on the bottom of the mouse still blinks.
Nothing

The mouse is about 3 or 4 years old, so (unless somebody else knows something I don't) I figure it's mousing days are over.

Has it gone to that big diode light in the sky?

Move the location of your reciever. Maybe take it as far away as the USB cable allows, operate the mouse right next to it see if it is still working. If not, then the problem is not due to rf interference and maybe the mouse is bad. specially, if your keyboard is working from the same spot (assuming keyboard is also wireless), then the mouse is bad. But, many times, problem is due to rf interference. By changing mouse/reciever location several times, you can tell if that is the case.