" I have local Non-VPN NAT 192.168.1.x"
This is a private address, NAT uses a different block of public IP addresses to get you to the "outside" web world.
When you open Network Security Map, I believe it also exists in Comcast version of NIS, does Norton "sees" your router??
Also did you initalize the Norton network miniport? It can be done when you open for the first time the Network Security Map Link in NIS GUI.
Regards,