I am trying to get ARC working properly on my recently acquired kit - a Pioneer VSX-321-k-p AV receiver amp and an LG 47LM620T-ZE TV. I want to be able to send sound from the TV (broadcast or internet-content, eg Netflix) down the HDMI cable to the sound system. Both devices support ARC. Sometimes it works OK, however it's very unreliable and often what happens is that the sound works fine for about 10 secs, then goes off for another ~10 secs; then the process is repeated another 4 or 5 times after which the TV appears just to give up, and it switches on its own internal speaker and plays the sound through that instead (ugh). Any ideas what might cause this? It's clearly not a loose connection or anything like that as it's so regular. I did wonder about the HDMI cable specs; the one I'm using is this Cablesson High Speed one, which should be OK? Any advice much appreciated.