The cause of the problems with the forums has been identified. A 1Gb+ file with a ETO expansion pack for CFS3 is hosted on our servers.
Due to the large number of simultaneous downloads the servers got overloaded and this had great effects on other processes on the servers. One of those was the fact the databases which contained the posts and threads got corrupt. In this process, which continued like a snowball, the back-ups went corrupt as well.
Well the good news is that we know what went wrong and are able to prevent recurrence. The bad new is that it is not very likely the old threads and posts can be recovered.
The massive file will be left on the server for two weeks then deleted, this gives the CFS3 people time to setup an DVD exchange program.