Well, it had to happen sometime. A hard-disk in our server started acting up and it looks like it's going to die soon.
To avoid outage problems, I've ordered a new server and have already started moving sites across (if you're reading this, then it means you're already on the new server).
Obviously, moving to a new server means lots of settling in problems, so please bear and accept our apologies as we try to resume normal services.
Update: The move has now been completed for all websites.
