Did you resolve this. I had exactly the same issue with new LG 65 inch TV. Used various high speed HDMI cables and was sent a new V6 box. Nothing resolved the issue. Problem was eventually resolved by Virgin engineer replacing the V6 with an older Cisco TIVO box. Not ideal but at least I have a workable solution. Not sure if the issue is the V6 or LG. My 46 inch Samsung worked fine with the V6 and the same cables and configuration.