I just tried to upgrade our sandbox running Fogbugz 8.1.1 Unix version and the previously working Custom LDAP configuration is now broken. We have been using the same configuration since Fogbugz 7 without problems. I helped another user by giving our example configuration a while back: here
The configuration is still the same and worked on 8.0.26. It looks like whatever LDAP fixes went into 8.1.1 have broken the open-ldap login method. (I also tried using the bare-minimum example configuration suggested in the site configuration page).