One of my WordPress 3 Multi Site subdomain blogs has vanished! It was available 'till a few days ago (last updated 26th June via MultiPress). The site's details are in the database. When I try to access the site I get a "Firefox can't find the server at sub.domain.tld" error, I cannot access the blog's backend through the Super User>Sites panel (same error) and updating the network gives the error "Your server may not be able to connect to sites running on it. Error message: Couldn't resolve host sub.domain.tld. Test sites setup properly and can be accessed without error. I've repaired and optimized the database.
It is as though my server doesn't know there is a subdomain site to serve. All my other sites work fine. Anyone have a solution? Where does WordPress register the virtual site to make it display when called?