Upgrade it already, 3.5.5 runs much better and barely uses any resources. I pretty much have Firefox open 24/7 and it runs just fine, just spent the last 3 hrs watching shows on hulu.
And NO Opera is not faster no way in hell.
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:18.104.22.168) Gecko/20091102 Firefox/3.5.5
Processes 104 Uptime 2 days Memory 232.6/493.7MB , thats in debian sid with lxde, lxterminal 3 tabs including shell-fm, evince, conky, and firefox.