is it possible that you tried to access the page with two different browsers? that's the most common problem. if that's the case, try using only one browser.
it's also possible that you're trying to connect from two different computers, which is also a common problem, in which case you should log out on one computer before connecting from another computer.
do you mean the top-right [login] link? if so, you have to log in from time to time, since your session expires after an hour of inactivity ...
you might also try clearing your cache and deleting your cookies.