ya. i found this on the net:
Be sure to get an MX1000 with an LZC5xxxx serial number though. You can make sure before buying (if you're not buying online) by looking at the box, you can see the underside of the mouse through the packaging.
If there aren't any LZC5xxx mice in the shop, you can always call up logitech and get a replacement, say that it doesn't work properly on USB, if they suggest simply to use PS/2 instead, say you're connecting it to a laptop and it doesn't have a PS/2 port. They will then issue a replacement mouse.
so... everyone with a MX1000, CHECK THE NUMBER!!! lol
im probably gonna sell my replacement and get a G5