With firefox, everytime I try to log in (regardless of whether or not I've checked the 'remember me' box), it always redirects me to the login page. (Redirect to login page if the reason I'm given the login page in the first place is because I'm trying to post or check messages... it sends me back to the index if I just log in from the 'log in' link) Haven't made any changes to this computer recently, and first noticed it last night but was too tired to post about it.
Just click on the profile link. It will send you to a login screen and then hit forums. It's done that to me for awhile and I get around the problem that way.
Now that I know that others have this problem, I would bet that it is a problem with Fugly. Maybe Jeff has stale cookies or something.