Your connecting to the server, but the authentication is failing. It doesn't recongnise your password, or username, or both.
---------- Post added at 16:49 ---------- Previous post was at 16:47 ----------
Have you tried working through the steps in this article:
http://www.cableforum.co.uk/board/96...ss-my-ntl.html
If you have, and still can't get in you may need to call support, to check your username and passwords are actually matching your webspace.