You have to run the repliesfix.php and THEN run the recount and rebuild tools in the AdminCP to get everything recounted.
I did that, and it did exactly what I told you.
I had to go through the recount rebuild to get it to be the way it was originally, maybe the post count will be a few more towards the real number, but I don;t really want to keep doing that the whole time.
Ok, PM me database login details for your forums and I'll take a look. I'll also need ftp access in case I need to run anymore scripts.
You're fixed. All you had to do was run this query:
UPDATE `mybb_threads` t SET firstpost=(SELECT MIN(pid) FROM `mybb_posts` p WHERE t.tid=p.tid)
And then recount & rebuild.