Ok, well it sounds like the ADNM console has it's IP address correctly configured if some are contacting it at least.
Sometimes firewalls on the client computers will block communication with the ADNM server. Check the Admin guide for what ports it uses and open them up if they aren't already (setup should have done this for you).
Also, the computer list is not "real-time". You have to click on the group or one of the computers and hit F5 to refresh the page. If you just leave it up, it'll never change the scenery...