TriggerFinger

Very strange. Honestly I have not seen a similar case.

This is a long shot but I hope you are going to try it. We need to know if it is Windows causing it or not. That being said, it would be good if you can try a linux live CD (like Ubuntu or Knoppix). No need to install as you can run it off the CD/DVD drive. The good thing about this is, if you are wired to the network/internet, you can open a browser in linux and simulate your situation of having several windows open. Try with touchpad and also with the mouse. If it acts up just like in Windows, then it could possibly be hardware.