I have used trials of the normal, Platinum and Pro versions of Sony Vegas 8 and each time it has a real issue playing back a preview for me. It's even so bad that just an audio track is sketchy. It's really hard to get any work done when you have to publish each project to see what you've done. My roommate has purchased Sony Vegas Platinum and is having the same problem, so I know it's not a problem with the trial. Both of us operate Toshiba Satellites with upgraded memory and upgraded processing speed. I've worked a lot with Windows Movie Maker and it plays back way better. What's going on?