just to say that I'm in the process of a complete re-install of the system software from scratch. I still can't work out what corrupted our database this second time, but there was also some disk corruption, so I've reformatted and we're doing it from scratch - taking the opportunity to update some of our system software while we're at it.
I'm also running every possible check of the database while I have it offline. It seems to be intact again, but time will tell. More info when I have it - hoping that rwg will be back up today.
Hopefully for a bit longer this time, although I STILL don't really have a handle on what caused this at the outset. However, we're on a fresh OS install, everything updated and the database passes every integrity check I can throw at it, so fingers crossed....