We recently had some trouble with our database and it had to be repaired. The forum is now running fine, but one particular forum is showing posts from August on the first page, so about 20-25 pages of posts are missing. Is there some way to rebuild the threads or some way I can try and get the old posts back?
When you are talking about repaired you mean with the Repair of MySQL or you just dumped the database and used a backup to restore/recreate it?
If it is the backup then the threads are gone if they were created after the time you took the backup.
Regarding the Repair function of MySQL I had seen in the past some corruption in the w3t_Users table of one of my boards and when I used the Repair function certain records were indeed missing (including one of my moderators <img src="https://www.ubbcentral.com/boards/images/graemlins/tongue.gif" alt="" />). So to the best of my knowledge the answer would be no (reluctantly)