I just received my Roku 3 today. I hooked it up to my receiver replacing another streaming device. It started up and the receiver (Onkyo) and tv started flickering with a signal for 2 seconds and none the next. I then plugged the Roku straight into the tv (Samsung LN46A650). No problems there and I got everything setup. I switched the Roku to 1080P reset the device and plugged it back into my receiver. The Roku video and audio is now working through the receiver to tv but the video has random horizontal lines flickering across it. It is really annoying. I tried going back and switching to 720P but then the receiver loses connection with the Roku again like it did when I first plugged them in together. Seems to be some kind of handshake issue?
Summary: Everything looks great when Roku 3 plugged directly into my TV. I get lots of flickering when plugged in through my receiver. Please fix this!!!