A possible cause is security software (firewall) that blocks or restricts Firefox without informing you about that, 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.

See Server Not Found - Troubleshoot connection problems and Configure firewalls so that Firefox can access the Internet and http://kb.mozillazine.org/Firewalls

Thanks for the reply.Ive run the tool EnumProcess and it found : Windows Firewall is on 5 Service(s) from AVG (AVG) detected antispy process from Ad-Aware detected I'm running the free version of AVG and this does not have firewall settings. However I did find windows vista settings and added firefox as listed in the configuring windows firewall.

Lets hope this fixes the issues .  ;)

Ok tested last night and this morning and it does hang now and then.

The adding of FF to windows firewall helped some but i still got the issue

Seems to happen if i run more than 2 windows (Tabs) at the same time.

I think i found why it locks up a lot.Addon IE fan 2 causes my FF to crash a lot.I will now remove that one.Hope this is helpful

(how come i get asked to log in even tho im alredy logged in? ) Its very anoying