I've got a folder on an external hard drive with videos in it taken from the 5D Mark II flash cards. I transferred them to the hard drive and the files were great. I've watched them several times since. A couple of weeks ago I upgraded to Snow Leopard (10.6) and FCP (7.0.3). The other day I went in this folder and all of the Quicktime files are corrupted. There is audio and the top third of the screen is fine. The bottom third is green. I saw a post about an upgrade to Quicktime a few years ago created this problem, but nothing since. I've tried manufacturers, recovery companies and utility programs. Nothing seems to fix it. Any one with the magic answer out there???

You need to find out if the files are truly corrupted, or if Quicktime (or one of its installed codecs) is tweaking.

Have you tried running the files on a different video player?

Have you tried deleting and reinstalling Quicktime? Or downgrading to an older version?