The forum we were using was constantly being spammed by bots for new user registrations, in a rate that made it impossible for us to keep it clean. I was making some modifications on the forum code to try to clean this bots/spam atack, and tried to clean up the thousands of pending member aprovals (that I had to turn on because of the forum spam).
So, finally I got tired and decided to try a different Forum software, and did so with the only one I found that seemed reasonable modern/updated, with some spam/bot preventions built in and that could import the old forum data: VanillaForum.
I have no idea was this will turn up, maybe I will have to revert to the previous incarnation. I hope existing/validated accounts got imported correctly, I did some work to not lose old links from google searches. I still need to learn a bit about this and possible tweak permissions and configurations a bit.
New user registration does not require aproval any longer, and hopefully it will prevent bots from registering.
Please let me know how it works, if you have issues, etc. I hope to have a bit more time now for answering things instead of dealing with bots/spams.