Enable middle scroll in Ubuntu Firefox

Here is how you can make Firefox under Linux act like the one on windows.

Follow these steps:

1. Type about:config into the Firefox address bar.
2. Look for general.autoScroll and set it to true
3. Look for middlemouse.contentLoadURL and set it to false

Source: http://blog.leion.net/2009/01/18/enable-middle-scroll-in-ubuntu-firefox/