As you can see the Forum is finally back!
We had enormous problems getting the new software to work on our servers, and then had difficulties converting all the old messages to the new format - many thanks to s_m_b at YaBB for all his help here!
The final problem was that we recovered all the 'lost' messages to an orphans folder and I have spent the last week moving these (2000+ threads!) to their original boards. I have almost certainly made some mistakes (or alternatively, maybe they are now in more appropriate places!) and so if you see any glaring examples of misclassification please email the board moderator or me with the details!