After reading a million threats I finally found the solution as to why I couldn't get trailers and home sharing to work without getting HDCP errors.
I have a brand new Samsung series 7 tV and 3rd generation Apple TV.
The only way it works is to connect the Apple TV to the HDMI port number 1 and set the name to 'PC'
I think this is because the Apple TV is basically a computer and the Samsung can't set the proper HDCP on any of the other HDMI ports
So it's not resetting or swapping cables but just the right port and setting.
Hope that helps somebody
I too have a new Samsung and 3rd gen appleTV, your solution above worked for me, thanks heaps.
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