After several days of "blackout", the GenABEL website and forum are up and running again.
After trouble getting access to our virtual server at Amazon's EC2 (which had unnecessarily been revoked), we decided to run the site at a different hosting provider, http://www.pcextreme.nl, which we also use for registration of the genabel.org domain name. Please let us know if you run into any problems/inconsistencies. We have tried to restore everything as best as possible, but we might have overlooked something.
Let's hope this kind of downtime won't happen again. At least we learned the value of good backups :-).