I use the middle mouse button a lot in Firefox. Using the middle mouse button when you click on a link opens the link in a new tab. Since I usually like to open links in new tabs, I do a lot of clicking on the middle mouse button. But when you miss the link and you click the middle mouse button on emptiness in Firefox, you get this crazy looking symbol on the screen and the screen starts scrolling around. Here's the symbol I'm talking about.

The firefox autoscroll symbol

I found out that this symbol is part of the autoscroll feature in Firefox. I'm not really sure what autoscroll is needed for, but for me it's just a pain in the butt since any time I miss clicking on a link my screen starts scrolling all over the place.

If you have experienced the same problem, there is an easy fix. You can turn off the autoscroll "feature" by going to Preferences, selecting the Advanced tab, then the General tab. In the Browsing section there is a checkbox named "Use autoscrolling".

If you uncheck this box, the Firefox autoscroll will be off and you can happily click the middle mouse button without your screen going all sorts of crazy.