I think I may have posted this many months back when the problem first occured however it then went away mostly and is only now coming back. What happened was- my input kept freezing up. My mouse would stop working for a few seconds then come back on with a loud system beep maybe moving full speed in one direction. My keyboard too would totally lock up (even not turning the lock lights on). Occasionally input would totally die leaving me having to reset the computer. This problem however mostly went away when I went away to university- my mouse still locked up on occasion but there was nothing critical. Now however back at home and its becoming a serious pain in the arse again. Not as bad as it once was but...still horrible. I'm on windows XP and am using a standard optical mouse and keyboard.
I can't remember ever updating mouse/keyboard drivers. And as I said this is a problem from months back that has just returned. I did have anti virus until a day or two ago andf I also regularly use hijack this and the like.