Forum User Accounts Randomly Deleted
 

This has been happening periodically over the course of a year, and we've ruled out administrators doing it manually through a careful review of our logfiles. Somehow user accounts are just disappearing from the database, leaving their posts as "Guest" status.

Has this happened to anyone else, and if so, what was the cause and the resolution?

We just upgraded to the latest version, and the server is locked down with mod_security among other things, so it shouldn't be a hostile attack (nor would that make sense for someone to gain access and then randomly, extremely sporadically, delete users).