OS X Yosemite clients

I am not able to authenticate users on OS X Yosemite (10.10.5) using OpenLDAP on a Linux server running slapd 2.4.40. This has worked with other versions (10.9, 10.7, etc) going back a very long time.

The logs and other tests (such as "id user") show that it is successfully accessing the LDAP data. It just won't authenticate with the password.

Has anyone successfully transitioned from OS 10.9 to 10.10 Yosemite with respect to authenticating off of OpenLDAP? What is the best forum for me to start digging into this problem?

-- Jon