My Firefox (now jumping to Aurora, and still having the same problem) frequently stops loading everything. I can load anything for a few minutes and then the browser will stop loading anything but doesn't show an error page, instead it loads something without stopping or finishing it. This does happen when I'm using Nightly when Firefox 5.0 is still in Nightly build but after I changed to the stable build it stops happening. Now it's back again.

Funny thing is, I tried every other browser and it works fine. I tried online games - connects. I tried IMs - also connects. There's nothing wrong with the antivirus too, since I don't see any rules in my Kaspersky Internet Security 2012 that tells the firewall to block Firefox or Aurora. And my internet connecting tells the same - no errors.