Not sure specifically on your problem, but some viruses play with your mind by frigging up your mouse.  AVG isn't bad, but if I suspect that something's wrong I run other programs as well.  Try Prevx, Spybot, Ad Aware, and McAfee's free online system scanner.  They're all free, but Prevx wants money for the registered version that removes problems rather than detects them.  It's a real company though, not one of the scammers.  It's possible that if you've been trying all wireless mice that you've got interference from something else, like a CB, cordless phone, or whatever.  Also, if your wireless mouse has a USB cord with an antenna that you mount somewhere on your computer desk, you might want to move the antenna or check that it hasn't fallen onto the floor behind the desk.  I had one that would give me fits if the antenna was on the left of the computer monitor and I used the mouse on the right of it.  Everything was fine after I moved the antenna.

 It's not a mouse problem, but my father in law had internet troubles at his house shortly after getting a new laptop.  He called in the techs from his service provider and they couldn't figure out anything other than go from his wireless router/combo thing that he was renting from them to buying a "real" wireless router and renting their other simpler modem.  Still had troubles occasionally and was pulling his hair out.  I came over to check things out and they were working great until the phone rang.  Turns out that one of the several cordless phones in the house would tromp all over the wireless signal when it was used.