Just a bit of help needed please folks, I've uploaded many of clips to youtube and I've never had a problem before, anyway, I've made a montage with about 15 clips in along with some music in the background which I downloaded from iTunes. The montage has uploaded fine but for some reason it will only let people view on their laptops and not on mobile devices. I've never had this problem with any of the other clips I've uploaded before, this is the first one that contains music, is this the reason why?? When I go into the settings of the clip, I see the option ticked where it says not available for mobile devices, but the box is 'greyed' out and won't let me untick it. Anyone help???

Thanks guys