I've noticed that the board occasionally gets confused as to whether I'm logged in or not. When it happens I have access to my home area (I can view PMs etc) but I have no posting privileges and there is no tracking of which threads are read vs. unread. I try to logout and then log back in but the "logout" button is not present. Instead there's a "login" button but when I click on it I'm routed back to my home page where my status is unchanged. In order to proceed I have to either clear my cookies or manually type in '...ubbthreads/logout.php' into the address field which forces the logout and then lets me log in normally.
This isn't really a big deal... now that I've dealt with it I can get around the problem in about 20 seconds... but it is a little annoying.