This has only happened to me in the last few days but when I try to play Neflix through my Apple TV box on 5.1 surrounded sound I get an annoying buzzing sound in the background on some of its content instead of the proper sound. This only seems to be contained to the surround sound track and not the sound coming through my TV. Just to note I have had to get a converter to be able to contect it to my surround sound kit as it does not initially have an optical connection in the box of the surround sound system. Just thought I would check if this has happened to anyone else or it is a problem at my end.