I've had my mac for a while now and one of the things I like to do occasionally is make music videos for movies and such. I've made a couple already and posted them on youtube with no problem. I was trying to make a video today for the movie A Scanner Darkly but when I edit clips together in the iMovie window, the clips are really jumpy and sort of bleed into eachother. this has happened before, but it was fine when I tried exporting the video. This isn't the case this time and I'm really annoyed. Is anyone familiar with this problem/know how to fix it?