My iMovie is being strange, I'e just imported all my clips to it, and now come to make a video, sometimes as I scroll over the clips, different clips show in their place, and the audio from one clip will play over another. Sometimes the video screen in the right hand corner goes blank. Basically it's useless. This is what happened last year on my old mac, and one of the reasons I specifically bought a mac (new one) was because I love iMovie and now the same seems to be happening again. I tried everything to fix it on my old computer, spent about 4 hours on the phone to apple but nothing worked. I'm livid.