Mouse pointer on screen.

[Seero]

For some reason once in a while the pointer on screen will move up or down while I'm using it or even when I'm not even touching the mouse. It happens sometimes and it started happening right after I sintalled SP2 for XP PRO. Oh the mouse is a PS/2.

[RoSpider]

The problem might be with your drivers which might missinterpret the data from the optical sensor inside the mouse or the problem can simpli be related with the optical sensor itself which might send erroneous data due to some malfunction. Try installing new drivers for the mouse. If this does not work I suggest purchasing a new mouse (if the problem is becoming to annoying). Hope this helps you.

Good Luck