Clean Your Mouse
I just changed the batteries in my wireless mouse and I noticed that there was some built-up "stuff" (for lack of a better word) on the various "turny things" (again, for lack of a better word). 30 seconds with a Q-Tip and WOW! I now have amazingly improved control over my scrolling. Well worth a minute out of your day, since I would guess that you haven't cleaned your mouse in months (if ever).
You don't have to thank me - you are welcome.
You don't have to thank me - you are welcome.