Ah ha! Here's the Apple Support article. It only works if the account logged in is a non-admin.
So one admin can't unlock another.

http://support.apple.com/kb/HT5145

Details of how to let other admins unlock other admins are also in the link. (In short: don't change the line from required to sufficient; comment out the whole line!)

Yes, The iMacs I'm working here all are joined by Active Directory.

Are you trying to unlock the Macs using an AD Domain admin or a Local Admin account on each machine. All machines should have a local Admin account deployed for correctness in Deployments using AD.

I think overall you should not be monkeying around with pam.d anymore ;-)
its all auth.db now ;-)

It worked for me when I logged in another account on a mac.. Works like a charm! Thanks again, agentx for all of your help!

Good i am glad i got that one resolved...i was getting confused !

help with Mavericks
 

Fairly new to apple and newer to Mavericks on my new apple air, first time here and could not see where to place a question but only how to ask...problem is I can't get rid of the reading list...if I go to the top tool bar and click on the right icon the reading list will leave but a new panel with messages appears on the right...click again and the reading list comes back...in ML I could just click on the reading list glasses and it would go away. Have gone to preferences and unchecked messages but does not have any effect ... can you give me a hint what to do.