The boys at YaBB released a new version of their forum software » YaBB 2.3.1. I installed a copy of this new script to a temporary directory .. see here » Y.231 temp (« this link will go away when the upgrade is complete).
I used a slightly different cookie at the new forum, so it shouldn't ruin your login at the current Rad forums.
The safest way to 'upgrade' the forums .. is to install a NEW copy of the most recent version (to a new/temporary directory) .. and configure everything at/for the new forum (.. while the old forum is running unaffected).
After everything at the new forum is hunky-dory, I'll put both forums in Maintenance mode (which takes them out of service), and then copy (via the cp command from the Linux shell) the files located in /Members and /Messages .. from old to new.
I think we have about 1,500 members and nearly 40,000 posts (in some 5,000 threads). Takes a while to copy all those files.