What kind of surface are you using? Sometimes if the surface is really reflective it can mess with the optics.  Also, check the connection between the wireless mouse and the reciever. If the connection isn't strong enought it can cause erratic behavior.

Best Regards~Justin~

I'll try the mouse pad, this one is years old, and I've switched back to the wired optic mouse. I scan for malware a few times a week due to the traffic to gaming websites my family visits. Thanks for the tips...I'll check them out.

I almost forgot...If you do switch mousepads and start using the wireless mouse again, be careful with dark mousepads. They absorb the light and can sometimes cause the batteries to run low really quickly. If it's wired, then you shouldn't have a problem.

Good Luck~Justin~