Does pam_group.so function on RHEL5?

Would anyone have some insight on how to get pam_group to function?

I've configured /etc/security/group.conf

Then made entries in /etc/pam.d/sshd
auth optional pam_group.so

Then connected via ssh, but to no effect.

Does anyone know of a guide to get this to function on redhat? I can find very little information on it.

Thanks