Mouse Pointer Jumps On The Screen And The Right-click Not Functioning?

I have run into a problem I haven't seen before on a HP desktop running Win 7 Ultimate x64. The users reported that when they open a window, ~30 instances of the window open at once. The error is intermittent, but since they shut down the PC after each use it may come and go with each boot. I looked at the machine and it functioned fine after several reboots, but eventually I was able to see some strange results. I didn't see the multiple windows open, but I did have some input issues. The mouse pointer would jump all over the screen and applications would open that were never clicked. The right click did not function correctly. Sometimes the context menu would flash on and off and sometimes nothing. I tried an alternate mouse and using a different USB port with identical results. I have run virus scans, malware scans and a registry scan, but no dice.