I am getting the same message. I am using Firefox 3.0.6 on Windows XP.
I've tried cleaning out the Temp folder of all files (including cookies as suggested by a previous answer in another post).
I've run virus scans and cleaned out more issues.
I've tried logging out/logging in, closing Firefox, rebooting...still happening.
I even changed my password in case my account had been compromised. It started back up again after that.
Sometimes it lets me back in, but eventually it starts happening again. I'd be inclined to think it was my computer if it weren't for the fact that so many people seemed to have suddenly hit this at around the same time I did last night.
So what's up and how can it be fixed?
