Just a thought besides checking for lint in the optical output port on the bottom of the mouse. How about simply changing mouse pads, sounds stupid and way too simple but recently that did take care of one of the Forums member with similar problems.

I have more wireless desktop sets (keyboard and mouse combos) laying around the house than you can shake a stick at. I keep chasing that neon rainbow when it comes to finding the perfect set.....still looking.

Finally, Keyboards and Mice are too cheap to be hassled with that sort of problem...just shotgun the thing out with a new one. if you have the same problem, then you now have a spare mouse and an obvious direction to go....shoot the computer.