I have just finished troubleshooting an issue where CSD was not showing agents. What I found to be the cause of the issue in this case was the version of the Cisco VPN Client (5.0.01.0600) installed on the Supervisor's laptop. The Cisco Systems, Inc. VPN Service (Service name CVPND) was started, when the CSD was launched we could not see agents or other statistics. If I stopped the Cisco Systems, Inc. VPN Service and refreshed the CSD, I could then see the missing information. When I started the Cisco Systems, Inc. VPN Service the agents and statistics would disappear. I upgraded the Cisco VPN Client to version 5.0.07.0290 and the problem was resolved. Everything worked correctly after the upgrade and the Cisco Systems, Inc. VPN Service running.
I tried this beacuse of am issue I ran into last year with the Cisco Unifeid Personal Communicator (CUPC) client not showing users status's.
Hope this is helpful to others