When I try to login with the Gmail email address the password is not recognised. So I proceed to reset the password. That appears to be successful as in his Gmail inbox there is a confirmation email from Virgin media. I again try to login with the same username and new password and get the same error message (password / username not recognised).
I suspect this account is somehow still registered with the old @ntlworld.com address however his Gmail account no longer receives those emails.
I tried to phone virgin media earlier today and after 40 minutes on hold the line went dead.