Okay, so having talked to our host, it seems like they moved us to a new server (they moved the whole server we were on to a new machine) this morning so the missing posts went to the old server. Why they didn't take the site offline so they had a complete backup at the time of the move I do not know. They assured me that the same thing shouldn't happen again.
Anyhoo - assuming that my access to the "old server" stays up long enough, I will try to copy and paste the missing posts tonight when I get home from work.
Conversations, though, I won't be able to copy (obviously) so I would suggest re-sending anything you sent around between 8 and 10 this morning EST (1p-3p GMT). (Obviously you can look in your conversations folder to see if they sent or not.)
Sorry for the inconvenience!