Repair WPMU site...

I have a small Word Press Mu site running. It just broke down, I dont know why, and need it back up, without loosing blogs or posts. It might be an easy task, might, not, I have not looked the the issue. Probably just some php settings. Don't know. Its being hosted by [login to view URL], and they say its software, not their host. I do beleive them, had have no previous trouble with it. I need a responsible person, with work ethics, morals, and sense of humor. ADDED The malfunctioning site is [login to view URL] The error is :No WPMU site defined on this host. If you are the owner of this site, please check Debugging WPMU for further assistance.