Make sure people aren't simply shutting down the rdp client as opposed to actually logging off. RDP for administration,as I recall, only allows two sessions. If someone is logged in and then shuts off the rdp client, the session is still active.
From time to time, we have been tempted to believe that society has become too complex to be managed by self-rule, that government by an elite group is superior to government for, by, and of the people. But if no one among us is capable of governing himself, then who among us has the capacity to govern someone else?
-Ronald Reagan, 1981 Inaugural Address-