I think, mike, you may want to try uninstalling the Folding on your PC and then reinstall it. Sounds like something busted on the original install. Might want to check and be sure a firewall or something isn't blocking the outbound traffic from it.
MC, your suggestion wouldn't work- he's folding on his computer, not the PS3.
Nice to see our new ranking- went to check it last night but they were doing another bit of maintenance on it at the time (seems to be a constant occurrence).