Well engineer just gone, he had not come across the issue before, told him the fault no, from this forum and the no of people, having issues. He then played back a 4K recording, and the audio issue happened straight away (thank god). He said nothing he could do, as appears a transmission problem with BT, he did ask wether I had changed Dolby Digital to Dolby Digital PCM, which I had done, but with no difference. He thought, that maybe that was the only thing, he thought might be doing it. It was left that he will raise another visit, for 2 weeks time, or hopefully a phone call to say, all sorted now, when he has spoken to the powers that be. He took down the fault no, and seemed genuinely interested in the problem. So def not sorted which I did not think that it would, but at least Virgin are becoming more aware of the problem. The more people that report it, against that fault no, the better, and maybe they will get the importance of getting it fixed. Back to watching recordings in HD, but hopefully something will get sorted.