Scroll Wheel / New Tab

As of yesterday my scroll wheel doesn't open new tabs when clicked, was a nice feature I used a lot. I was curious as if it was the mouse itself that is broken, or if I had unchecked a box that allows the ability. Future feedback is appreciated.


**EDIT**
It does work in Internet Explorer, but will not work in Firefox 3.5.2

**EDIT**
This thread should be moved, as I noticed the other sub-forums, sorry for the troubles.