"Unknown message!" for DDNS status

The usual first steps to troubleshooting update problems are:

1. Check that the date and tme on your WRT54G (?) is correct
2. Check that you're running the most recent firmware
3. Check that you've correctly entered your username (not email address), password and full hostname (myhost.example.com)
4. Check that your password only contains letters and numbers - some clients are picky about the password
5. Check that your hostname exists in your account