What happens when you follow the advice given here:
http://www.cableforum.co.uk/board/article.php?a=30
Edit: just a thought, but your user name should be the
original one from when you first set up your ntl account, not one you may have changed to. If you have ever edited your master user name, I found that
did not change the user name for the web space. Similarly the password is most lilely the original one assigned to you be ntl when your account was first set up (you may need to find the original account welcome letter or CD), rather than any new password you attempted to set up.