cursor moves by itself

I'm having a problem with my mouse/cursor. I'll be doing something (internet,gaming,writing a paper,etc.) on the computer and all of the sudden the cursor will move 2-10" in any direction(up-down-left-right). It just happens out of the blue, but it seems to happen more frequently around animations/java applets. I've run my virus scanner several times, checked to see if anyone put a gag program on my computer, reinstalled the drivers for the mouse, cleaned the mouse/mousepad, checked the device manager for conflicts.....I don't know what else to check. It seemed to start around the same time I installed a new game, but I've uninstalled it since and the problem still persists. My computer is/has:

Dell 8100
1.3 ghz
128 MB DDR
32 MB Nivida GeForce 2 MMX
Soundbalster Live
40 gig HDD
Windows Me

Any help would be greatly appreciated.

 

If you have not updated your antivirus program recently, it could still be a virus.