My iPhone 4s was having the same issue with the video not working. After I upgraded to iOS 6, I lost all usage of my phone. No ipod, no pandora, and now I get the "charging is not supported with this accessory" message when I plug it in. It also wont work with an iPhone 3gs running iOS 6. Major bummer, as I used pandora all of the time......
I have a avic f900-bt with firmware 3.something and the parking brake wiring mod.