An update. I bought a new Wireless Explorer today, and after about 5 hours of testing all seems well. So, I guess my previous mouse--of not that old of a vintage--was the culprit of all my problems. Me and the kids put it through hell, so I guess I gummied up the works or something.
I'm glad it was a simple fix, although not happy about shelling out $50 for a new mouse.
.gif ":mad:")