I'm trying to upload a .mp4 file to youtube, but every time I do, it ends up looking like thishttp://www.youtube.com/watch?v=3RcdsCK4eCs and won't play properly. I export my video from Adobe Premiere Pro in H.264 at the settings that it recommends, but every time it ends up not playing properly. Does anyone have any idea as to why this might be? Help would me much appreciated as this is becoming exasperating! If it makes any difference, I'm a mac user.