Quote Originally Posted by aerowing
... Could it be because it is optical mouse?....
PS2 optical mice generally work fine with Knoppix (as far as the interface is concerned the software doesn't treat it any different than a mechanical mouse, the optical stuff is all done in a micro on the mouse). I don't know what the problem is, but I doubt very much that this is it.

You might try looking at the BIOS and see if you have any settings that might apply. Look for cryptic things such as "legacy support". It may also help to post the make and model of the computer, and make and date of the BIOS, someone with the same hardware might come across it and know your issue.