I also agree with Rob, I'm new to the world of Cisco and just recently discovered the config software for the 7920's. The firmware on the phone has to be a 3.0 or higher for the software to program the phone settings.
I am also having this same exact problem. I can talk to others with VT advantage and video works fine. This new phone I have setup does not work at all. No video, just the voice via the hand set. Both PCs are using VT 2.02.Turned off the firewall...