I recently hooked up a Sony kdl-46ex400 via hdmi to a cisco chs335 settop. I noticed that when I turn on the TV, the settop does not respond for several seconds (maybe 30 sec) to remote control commands. The channel that was previously tuned is still being displayed ok--it's just the control of the settop is lost for a while. The power led doesn't even flash to indicate that the settop received the command.
So far I have tried turning off control over HDMI (HDMI-CEC) on the TV and nothing changed. I contacted Sony yesterday. They confirmed I have the latest TV firmware, but otherwise don't have any ideas. I suspect there is something going on with the hdmi interface at TV startup that is causing this glitch on the settop. I will also try a component connection, but wondering if anybody else has noticed this problem. I have several of this model settop hooked up via hdmi to different TVs and they seem ok.