I was running iMovie2 flawlessly in Jaguar on my G4 466MHz with 512MB ram. It was fast and interestingly, the effects and transitions acutally render faster in iMovie3. It's just things like saving a project, deleting a clip and undoing a command that get my "rainbow ball" spinning. I end waiting for almost a minute for these actions to finish. It seems to me that if rendering would not be so effective for me if I truly needed a faster machine to run this program. In other words, why are some actions so slow while other processor intensive actions (like rendering) faster than before. I optimized my LaCie external HD before starting the project as well. Pam