It is possible that the server is temporarily down, but when that happens it usually just tells me I have the wrong password till it is back up.
Edit: I just checked the time difference between your 2 posts, seems rather long for an outage. Do you have a second computer on that network that you could test it with? If not, you might want to start troubleshooting the app itself. Permissions, fsck, and possibly dragging the prefs out of the prefs folder temporarily