I am working on Ubuntu 12.04 using Firefox 13.0.1. Out of the blue, Stack Overflow stopped responding. If I request http://www.stackoverflow.com then the index.html page returns, but before Firefox renders anything, it stops.
Firefox's error console shows nothing - not a single message.
I can open sister sites like http://askUbuntu.com without any problem. I can also open Stack Overflow with Chrome.