I did some quick research about it, and it doesn't seem to be something that has a conclusive solution. A lot of people experience it on laptops if they have both the touchpad and a third-party mouse installed, since it creates a resource conflict or something like that I think. That's probably the only reasoning I had seen for it though.
Also noticed it seems to happen a lot on Dell machines, or more specifically Dell laptops. I have an HP desktop, so I don't know what the heck is up with me, but it might help you though.
In anycase, I've seen a number of solutions. Some people say to reinstall your BIOS driver, some others say to reduce the speed of the mouse or scrolling. I have seen one thing though that looks sensible. Someone suggested it's a corrupted mouse driver and needs to be reinstalled. It sounds like you had gotten your mouse from some other source than the original computer, so that may be the solution?
This is a really bizarre situation, I wish there was a more definitive solution. Maybe one of the Tech gurus on this forum can chime in?