Sounds like you are most likely running a client that is patched to EQLive. You can check your client version by following the info here:
http://www.eqemulator.net/wiki/wikka...ClientVersions
If you patched to Live and can only connect to that one server, then my best guess is that they recently updated their code to the latest SVN and no other server is running the latest yet. Derision just updated some of the opcodes and such to work with the Live (or maybe Beta) client. I don't know how many he updated, but probably not enough to fully log in a character, or at least not enough to play is my guess.