Update
Sometime either over night or tomorrow I am going to install a new set of clean, upgraded files which I have been supplied by vBulletin. It's not a simple operation and I have an awful lot of reading and preparation to do before that can happen.
I sincerely hope that by doing that, not only will all the missing photos re-appear, but that all these stupid, niggly little errors that have beset the forum in recent months and which have been driving me mad, and I have no doubt everyone else too, will be laid to rest.
The database will be backed up over night, as it is every night, so if anything is lost, which I'm hoping it wont be, the losses will only date date back as far as this evening.
You should be aware that the forum will be offline for a short while to allow this to happen. vBulletin have suggested a working method to minimise the downtime, but in truth I have no idea how long it will be. However I'm guessing it will be a matter of perhaps an hour.
There are two worst case scenarios - one is that the forum is down for longer, in which case you will know it hasn't gone to plan. Don't despair though (that's my job!!) You can rest assured that I will be doing everything possible to mend things as quickly as possible.
The other worst case scenario is that the upgrade fails to retrieve the lost photos, in which case I will have no option but to restore them from a backed up version of the database from before the time that they vanished, which means that all posts made after Friday night will be lost.
I'm painting a black picture though - hopefully all will go smoothly and nothing at all will be lost. However, you can expect the forum to be down for a short time in the next 12 to 24 hours.
Thanks for your patience.