Sorry, bunty, no idea. It works for me.
Sounds as if you can log in, but the problem arises when you click the
Submit button.
I don't know what chain of links you get.
Try this link:
http://www.guardian.co.uk/crossword/genius
If you still have problems, e-mail them:
userhelp@guardian.co.uk
crossword.editor@guardianunlimited.co.uk
Good luck.