Buggy mouse wheels are really weird. I think all we know is when you scroll down and the document jumps one step down, two steps up. It can get really annoying.
But the weird thing is that sometimes it is just a matter of cleaning. You remove a couple of screws, open the mouse, blow on the wheel a couple of times and put it back together again. But sometimes this procedure really does not change anything. And then I have absolutely no idea what is happening. And it happens with the optical sensor for the wheel, just like with the mechanical rotating 'counter', and I really am not able to find a way to fix it. So I would appreciate any opinion on what causes this behaviour, because especially with the optical sensor I cannot imagine any material fatigue.
Jan "Jenkings" Škoda - blog
Simplifying IT, Amplifying Knowledge