I thought about this a little more, when I go back to
http://www.vsfan.org/forums, it's a "404 - Page not found" error - not a DNS or Domain expiry problem at all. Plus, if DNS wasn't working at all, then the homepage wouldn't even resolve to the GoDaddy page.
My guess is one of the following:
1. If he's currently hosted with GoDaddy, they might've screwed up and lost his site data
2. If he's currently hosted with GoDaddy, he's removed the site himself
3. He's switched hosting companies to GoDaddy and he hasn't put the site up at the new server yet
Cheers
Michael