Currently Being ModeratedMay 9, 2012 12:31 PM (in response to drwebmail)
I have pinned the issue down to Quicktime X. If I open the file in QT X the video stutters (max headroom effect) and then I get graphics problems and my system locks up for a bit. Then I can reboot. So I proceeded to get rid of Quicktime and then noticed that Snow Leopard has both Quicktime X in the Application folder and Quicktime 7 (used apparently for itunes) in the Applications>Utilities folder.
I tried reinstalling Quicktime X and it did not solve the problem. Now I have tried removing Quicktime X (drag to trash, empty, and reboot). When I went to open the file I noticed it still had the quicktime X icon and when I checked get info I noticed something called Quicktime Player Launcher was assigned to open the file. It is my understanding that this is part of Quicktime 7 though. So I did an Open with... Change All to Quicktime 7. Then I opened the file with quicktime 7 and there are no playback issues or graphics problems or lockups. I also open the file in VLC, soundtrack pro, etc and everything works fine.
However when I preview the same .mov with quicklook, I have all of the same issues and my system locks up to the point of needing a forced shut down.
Is there some way to clear the cache of quicklook or reinstall the quicklook components. There must be something corrupted in there or some Quicktime X plugin used for quicklook.