just an idea: how about to check server's db if the account got somehow banned by server?
btw. the bug happened to me too, it was after two crashes of client (client just exited to desktop without an error message). since the second i can not log in the account after server selection
note: i tried to log in on test server with this account after this problem. not working
note: i can confirm, that creating a new account and using it to log in on same computer on same everquest installation, just while the previous can not log in, can be successful. making /who otherchar gets no result, so it is not the character getting stuck
note: using stuck character mover will not solve the issue