FIrst - please post in the appropriate forum or use the Help Center. The Rants, Rave forum is not the appropriate place for this question...it has been moved.
To answer your question:
The site was moved this weekend...to a new server. That's why it was offline on Sunday. The move caused the site's IP to change. If your ISP hasn't picked up the change (usually takes 24-72hrs to propogate globally) then you are still connecting to the old server. The old chat server is still running and that's why you get a partial connection. However, the user authentication piece is here and the old server can not authenticate you, thus no chat for you.
Give it a bit longer and you should be OK within a day or so at most. I assure you, the chat is just fine here. There were something like 20+ people in it at one point last night and there are people in there at the time of me typing this.
Have some patience.
