I'm having trouble with my seq in FCP 6.0.6. I'm editing a short film and have done an assembly edit with the original h264 files with no playback issues. I've now moved onto a new seq editing all my trans-coded prores 422 files and I'm getting playback problems. The files play for a few seconds and then begin to stutter and I loose the image. My scratch disk has 70gb free on it and changing the rt settings makes no difference.