I only see myself in Facetime video

This is the first time I have tried to use Facetime. I called a friend that has an iphone 4, we were both connected to different home WiFi networks. I would initiate the call & when she answered would hit the facetime button. We could both hear each other but both only could see ourselves in the video. There are no camera buttons, etc. to change view. I have followed the Apple Instructions for using Facetime that has been posted at various times within the Facetime Discussion thread. I have a new iMac with the Airport extreme router. I have read that the port forwarding must set correctly. There is another statement that says most WiFi networks will work automatically with video calls. Is this my issue? My friend has used facetime with other people just fine. However in the call with me had the same issues as I did. Any thoughts?