I recently moved to a new apartment and finally had a chance to work on some better A/V experience. Just got a RX-V475 yesterday and hooked up my Samsung UN65F6350:
Comcast HD Box (HDMI out) ---- (HDMI 1 in) Yamaha RX-V475 (HDMI out - ARC) ----- (HDMI 2 in - ARC) Samsung TV
I connected TV and receiver with ARC with no problem but now I whenever I boot up my TV the receiver switches on and automatically switch to AV4 (default for ARC TV) despite I want the audio from HDMI 1 (cable box). I had no problem getting sound from all the apps (netflix, pandora... etc). Just every time when I turn on the TV (and the receiver) I need to manually switch the receiver to HDMI 1 (to get sound from Comcast Box)... I googled and saw many people had the same situation (wouldn't call it a problem) but the only solution seems to be running another optical audio cable from TV to receiver and disable ARC? (So whenever I need to use TV apps I switch to optical input).