Yesterday, I made a movie in iMovie with clips from my GoPro HD Hero 2. iMovie was going to let me upload in 720p at that time, but I waited to make some adjustments (just splitting, deleting and moving clips). I now tried to share to YouTube today and iMovie will only let me upload in Large format. I don't understand what could have changed with the clips as I didn't reformat them or anything. Vimeo is having the same problem as well. Any help is appreciated!