And don't forget to wipe out the db, especially when it's just a test db, when you change build version. It shouldn't matter, except occasionally when changing minor version number (the X in 2.X.Y), provided everything was built fine, but it would clear out one possible source of erratic behavior, just in case.
This appears to have been exactly what the problem was. Clearing out /var/lib/ldap did the trick. The system appears to be working as before.
Excellent!