I have 2 users (that I know about) that can not log into the
conferencing client. I have the ldap-sync checking for users by their
membership in a specific group. If I remove them from the group,
ldap-sync reports 2 less users. When I put them back, ldap-sync
reports 2 more again.

I've run dstrace on the ldap server that gets queried, and I see the 2
users being sent to the conferencing server during ldap-sync. But, I
don't ever see anything for those users in the trace when trying to log
into the conferencing client. For all other users I see trace info
when they log into the client.

I've tested the users on my system, and I can't login with those
accounts, but I can with mine, and others. Others in the same context
work fine. I can't see anything different about these than others.
I've also tried changing the passwords. The fact that I don't see
anything in the trace for these users is troubling.