I have a USB mouse on my notebook (my main Knoppix system) and it has never failed to work. Yet you are not the only report of USB mouse problems I've seen. I would suggest first, if you have one, try another USB mouse. The problem could well be Knoppix and your motherboard hardware however. Recent versions of Knoppix seem to have more USB problems than old versions (this just an observation from the posts here; I have not seen them first hand). You didn't say what versions of Knoppix and STD you are using. If it's the recent versions of both you might want to try something older (pre 3.9 on Knoppix or the 2 year old version of STD). If these don't work then I'm out of ideas, but if they do then you know it's the recent Knoppix USB bug that a few others have reported.