I've had a similar problem. After I upgraded to Firefox 6.0.2, the browser seemed to exhibit severe performance issues. Previously, I'd been using Firefox ever since Firefox 3.5 with no issues.

Also, interestingly, when a site is slow, the entire browser now seems to hang and I got repeated messages from Windows saying that Firefox was not responding. As far as I can tell from my 20-30 minutes of trying to use 6.0.2 under Windows 7, it's unusable for me.

Luckily I was able to find Firefox 6.0.1 somewhere and was able to go back to using that -- it was either that or start using a different browser altogether. Also, I've learned my lesson and disabled Firefox update checks going forwards. I'll probably do manual update checks once in a while after the release has been out for 3-6 months..

Thanks for the suggestion but I don't think that is the problem. I also have Firefox 6.0.2 and IE Explorer on my laptop (which is also running Windows XP) connected to the same router as my desktop with the problem. On the laptop Firefox loads pages fine. There is no difference in performance between Firefox and IE Explorer. I think it has something to do with the Firefox settings on my desktop but I can not find any differences between those on my laptop and those on my desktop. Or it may have something to do with the extensions or plug-ins.

I am so frustrated with Firefox! Pages will not load. When clicking a link in email it just sits there. Same with bookmarked pages. IE no problems. I have a fast computer so it's firefox not the computer. They refuse to address this problem which has been going on for months!

I've been using Firefox as my default browser for years... I had my cable company on the phone and they couldn't figure out why my internet was so slow because the tests they did indicated I should have a very fast connection. After 45 minutes with the cable co tech support, he suggested that I check my connection speed with other browsers. I tested speed in Internet Explorer, Google Chrome and Safari... ALL of them were working super fast.

After realizing Firefox was the problem, I was searching (using Google Chrome browser) for a fix to the speed problem. One person said they installed the older version (6.0.1) and that corrected his issue. I uninstalled 6.0.2, installed 6.0.1, but it was just as slow as before.

Unfortunately, I don't have any more time to spend on this issue, so I just changed my default browser to Google Chrome.  :'(....

A possible cause is security software (firewall) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.com/kb/Server+not+found
• https://support.mozilla.com/kb/Firewalls

You can also try to disable IPv6

• http://kb.mozillazine.org/Error_loading_websites#IPv6