Hooked up Roku to Samsung Series 6000 LED TV via Roku provided HDMI to watch Netflix movies, worked perfectly for a couple of days...then suddenly today the dreaded green screen. Was on the phone with Roku customer service, unplugging and plugging in HDMI cable, Roku box, even my wireless router...no luck. Also tried other HDMI input, no luck. When I unplug and plug in the power cable from the back of the Roku box and choose HDMI source #2 where the HDMI is plugged in, I briefly see the Roku screen flash on (teasing me) then it goes to an "unsupported mode" message which moves about the screen for about 30 seconds, then the screen goes completely green. This didn't happen at all for the first couple of days; it worked fine, easy setup. Discouraging. Will have to return this if it takes up any more of time!
Sounds like a possible HDMI handshake issue with the TV. I am sure, that somewhere there is a lively debate going on as to who might be at fault, (Roku or the TV manufacturer) but I am fairly confident that if the TV manufacturer wants to figure it out, someone will be happy to work with them.
If you don't want to spend the time to get your network all working together though, that is fine too, but if you DO decide to resolve it, and have any questions, feel free to ask. Usually folks end up figuring things out with the help of the people that use these forums.