well i can't really do much if i don't have anything to act on, the day before yesterday (when i got a mail telling me the site was down) a certain service errored out after which there was an abrupt end to anything being logged for couple of hours but i didn't see anything for the time you mentioned
can you tell me what exactly happened?
anyway the only thing that's left for me to do would be to wipe the server completely and reinstall everything