Hello. I have a bit of a strange issue. I'm using iMove '11 in Lion on a 2.5Ghz, MacBook Pro 4,1 early 2008 with 4GB Ram and 500GB 7200RPM Drive. When I try to preview clips from the clips browser, by moving the mouse to a position and then press space, the movie will only play for a second, then the video stops, but Audio continues, and the marker moves, video will sometimes update a frame, but it is pretty useless. I first noticed this now when moving to Lion, I haven't used iMove for a while, but I know it was working before in Snow Leopard as I have edited a few movies before. Now this is happening with clips I have previously used in other projects. The strangest thing is, that if I add the clip to a project and then play it, it works perfectly fine, even full 1080p@25fps clips play when added to a project. I made a few changes to the system so I'm not sure which one created this error: Clean upgraded to Lion. Moved from iPhoto to Aperture, (No iPhoto installed anymore) New Camera, Canon DSLR instead of iPhone for recording Video. The clips will also play fine in Aperture, or in fullscreen Quicktime, it is only in iMove that there is an issue. I tried to uninstall iMovie, and reinstall from Appstore, I use AppCleaner t uninstall and it removed preferences and various files spread all over the drive. But the issue is the same, any Ideas?