As described earlier, it is the middle mouse click that changes the mouse pointer into an arrow with a vertical scroll bar. Before you try the following suggestions, click anywhere on your screen and ...

I have a Razer Abyssus mouse and my scroll is not working as intended - when I try to scroll down for example, it tries to scroll both ways simultaneously, it goes down several lines then up several ...

Speaking only of the default Windows & OSX mouse drivers...<BR>When I use the mouse wheel to scroll in OSX (10.5) it seems to be able to detect whether I "flick" it quickly, or slowly turn it.