Thread:Extension talk:LDAP Authentication/Active Directory group synchronization problems/reply

There is a possibility I never tested memberOf with group synchronization. It does indeed look like I'm not setting a short name there. Try this:

Of course, you'll also need to set $wgLDAPGroupNameAttribute in your settings. If you are using AD, this will be "cn".

I haven't actually tested this code, as I have no quick way to test this right now. Let me know if it works, and I'll commit it.