LDAP credentials fail for MySQL

I've been working to get Virtualmin setup on a RHEL 6.2 system and have run into a snag with LDAP credentials not working for phpMyAdmin/MySQL authentication. I've verified LDAP credentials work successfully logging into the RHEL system itself, but no luck with logging into phpMyAdmin via http auth, or to MySQL via CLI. I'm thinking it's got something to do with password hashing, and I've toggled settings within the MySQL and LDAP modules to try various things without success.

Ideas?

-Joe