So...I officially give up. I have a lot of avis with mutiple audio which I converted to .mp4 so I could add them to my iTunes library and watch them on my Mac, my PC and my AppleTV. So I added the mp4s to iTunes and tried them on my AppleTV. In the ATV settings I chose my prefered language and it worked. Perfect. So I went upstairs again, opend iTunes and it played both soundtracks at once (what the **** are you thinking Apple???!) so I googled and found a "trick". Open Movie Properties, disable one track and save as a reference movie. So I added the .mov to iTunes and thought: yeah it works. There is a speech bubble in iTunes where I can select the track it plays. One question right here: why doesn't this work with the normal mp4?! So I was happy. Everything worked out. 3 Seconds later: A popup told me that my AppleTV can't play this video file. I can't take it anymore. Is there a solution for this? Am I the only person on this damn planet you wants two languages in a movie and watch them in iTunes and on the ATV?