Hey guys have you ever looked at the side of the scroll-thingy on your mouse? I bet, if it's anything like mine at work, you have about 3 years worth of crusted up linty dirt stuck to the sides of the wheel down by the clicky parts of the mouse.
So, maybe give yours a swipe with a Lysol wipe (and tweezers and a finger nail and a pencil) like I did. I clean the thing whenever I wipe down my desk but there is a little nook there that I never paid attention to.
I think this qualifies as a public service announcement. And I think I need a Silkwood shower. Maybe some antibiotics. Ick.