I also noted another error casued by the mousewheel. When in game if I accidentally touch it, my mouse cursor gets stuck at the middle of the screen. I can move it left and right, but when I move it up and down it immediately goes back to the middle (vertically).
On a side note, I had previously gone under:
control panel > Mouse > Motion
I unchecked the box maked \"disable acceleration in games. I initially had it checked and this caused my cursor to be slow (like others were reporting on the thread). By checking it my cursor was very responsive and working great. I\'m using a logitech mouse under XP so I\'m unsure if this option is available to all.
I\'ll try undoing this and disabling extra functions to see if this fixes the issue.