When i put the first video onto the timeline or into the preview monitor and either press play or start to skim through it, the program just crashes and i have to start it up again. This happens every time which actually makes doing anything impossible. I'm using a Macbook Pro. It doesn't slow down when i open the program and doesn't show any signs of lag. I can play spore on it on perfectly good settings so i don't see why simply playing a video on the timeline in Final Cut Pro would be a problem. It has no problem doing that in iMovie or Adobe Premiere Pro (which has it's own problems) so I don't think it's a question of lack of RAM. The videos i've used are .mov files. Any ideas?