All,
I finally discovered my problems for both living room and bedroom and thought I would circle back and share:
Living Room - I was using a powerline that must have had issues. I switched back to my ethernet line and this Apple TV would work with both Wireless and Wired connections, all content.
Bed Room - I took ATV in and got replacement. Works great at first but then wireless started not allowing playback to begin, even though I could see the movie buffering ahead. So hard to believe 2 ATVs in row would have same issue. I then switched the ATVs between bedroom and living room. The one in the Living Room that worked fine in the living room but not in bedroom. THe one in bedroom wouldn't stream in bedroom over WiFi, but fine in the living room. So it dawned on me. I have to have some sort of wireless interference in my bedroom. The signal was full bars and the network test would pass every time.
I have a Samsung sound bar with wireless sub. It operates on a 2.4 and 5.9 frequency. I decided to turn off the sound bar when the movie would buffer but no playback would start. As soon as the Soundbar turned off, the playback started on the ATV. I would let it play for a while and turn the SoundBar on. The ATV would keep playing until it reached the end of the buffered movie. Then it would stop and start the endless circle. My soundbar connects to from my Samsung TV using optical. So its HDMI to Samsung TV, and then Optical to soundbar.
I discovered this at about 2am last night (I am dragging at work today, BTW). BUt it was driving me nuts to figure out what the issue was. I tried setting up a 5ghz network and connecting to it. Still had the issue. I may need to try a diff frequency on my router for this band. The Samsung is suppose to automatically change frequencies to avoid conflicts. But apparently not in this case. i still have a ways to go and find the true root cause. It could be the wireless, it could be the optical/codec connection for the audio, or maybe even the older HDMI cable I am using. But I have established it is NOT the ATV itself. The ATV works great in any other room.
What is even more bizzaro is Netflix and Hulu stream just fine. Its only when I try to do specific movies from iTunes on my iMac or my iTunes in the Cloud. LIke I said, a ways to go. But I wanted to bring this to everyone's attention who may be at the end of their rope and maybe was too focused on the ATV, Network, and IMac setup to consider it was another component in their setup!
I will report back if I find a final root cause/solution. But I hope this helps you get on the path.
Chad