FF 3.5.1 Server not found message

[towerchariot]

For the past few days when I attempt to go to some websites I get the "Problem loading page" screen, but when I use the IE tab add-on it loads right up no problem. I've cleared my cache, ran my virus scan (avast), used Malwarebytes, used CCleaner, and ran Ad-Aware. None of those picked up anything. I have no idea what's wrong or what to try next.

Thank you!

[dedododo]

I'm having the same problem with FF3.5.1, but sometimes it starts working if I wait 15 minutes or so.

I have no problem accessing the same sites (e.g. www.time.com) in Opera even during the period when FF fails.

[iguy07]

I just tried to upgrade from 3.0.12 to 3.5.1 yesterday, and had the exact same problem. Random websites (like google and newegg to name just 2) would give me the "Server not found" error when attempting to load them. I even tried running Firefox in safe mode with no extensions and all my little "tweaks" disabled, and it still did it. I eventually had to roll back to 3.0.12 because I couldn't figure out what was causing it.

[AZRainman]

Been having this problem too and tried a variety of suggestions, but it still occurs... although it is considerably less frequent since disabling dns prefetch.

More here:
Server not Found, so What's the Fix?

[USER080209]

Also been having these 'Cannot find the server' or 'Page not found' type errors frequently after the 3.5.1 upgrade.
Hitting the reload button a 1/2 dozen time sometimes works, but a few times I have to shutdown FF and fire it up again and it then will connect 95% of the time. This can be a pain when FF gets these hiccups.

[download13]

This has happened to me as well.
After a while I found that my gateway had an IP address conflict with my Linux box and thought that was causing it but
after fixing the conflict the problem still occurred.
Usually it won't load, then I wait about a minute and try again, then it loads just fine.