I posted in another part of the forum and it's not getting much response so I'm bringing this to the Media Centre section
My other thread was http://www.raspberrypi.org/phpBB3/viewt ... 48#p147548
Basically, whenever an unpowered Raspberry Pi is plugged in to a system with CEC control set up, it completely screws the set up and the devices will no longer communicate properly. And in my experience, only a factory reset of the TV set (which is the main control unit of any CEC set up from what I can see) while the Pi is either unplugged or fully powered up will allow it to detect devices on the HDMI link.
From what I can tell, from the moment it's introduced unpowered in to the loop, the TV is no longer able to send commands down the HDMI channel and I have tested this with it connected via my AV receiver or directly in to one of the TV's HDMI ports. Which ever way it goes round, the TV and a unpowered Pi do not get along.
So far, myself with a Sony Bravia TV set and also another user with a Philips TV set have reported the exact same issues and conclusions as you will be able to see in my linked thread above. I don't know if this is just the odd defective board or certain TV sets flake out under certain scenarios but I'd like for people who use the Pi on a system setup with HDMI-CEC/Bravia Sync or any other name a manufacturer has given it and if they read the linked thread to then give feedback about any issues you may be having.
Even if you do not use the Pi as a media centre, this can still effect you if you plug it in to your TV set since your other devices will no longer be controlled by the TV and auto-off/channel switch etc.