Recently Firefox 2 has been really slow compared to what I'm used to. It seems to stop working when I click on another page or refresh the current one, this happens very often, I'm speaking at least once every 2 hours.
I've tried reinstalling Firefox, but it didn't work. I only have a few plugins now: Fasterfox, AVG safe search, AVG secruity toolbar (which I dont use), download statusbar, Google toolbar for firefox (which I have tried getting rid of multiple times but can't) and Talkback.
The solutionThis is most likely caused by AVG safe search or AVG security toolbar. I would try uninstalling the AVG security toolbar first. (You could try disabling it and seeing whether that makes a difference). You can access the toolbars by selecting Tools > Add-ons.
I'm using AVG myself, and I've uninstalled the safe search feature as I found the icons annoying. I haven't used it long enough, to see whether it made a speed difference, but I believe this may be the cause of the issues you are experiencing.
The page http://free.grisoft.com/ww.faq.num-1338#faq_1338 explains how you can remove the safe search/link scanner from AVG.
[disclaimer]Please be aware you will have no link scanning protection anymore and you will have to pay attention to the sites you are visiting.[/disclaimer] Personally I think the faster surfing is worth the risk, but you will need to be aware, and don't come crying to me if you click on an "evil" link.