check your domain info for typos and errors. i have a friend who typed the wrong domain in his email info - it is his domain, but the email he put there isn't one he uses.

the registrar has his contact info, but they said they were required to get in touch with the site owner via the email address on the domain - he found this out when he discovered his domain was down. thank goodness the registrar acted fast after he fixed it! some registrars take a lot longer.