I just noticed that some of my Canon S-90 camera video clips had missing preview icons like they usually have (instead it came with generic Quicktime icons) in Finder and furthermore found out that they were unplayable in Quicktime ("File is not a video file"). Following some other threads on the same subject I followed a suggestion to try opening the files with VLC. To my surprise they all opened and played perfectly! So I assume the header or something minor is damaged, while the video/audio itself is intact. How do I fix those files so they will also play in Quicktime Player? I'm on a dual core iMac running MacOSX 10.6.6 and have both Quicktime X and Quicktime 7 player installed (I find the Quicktime update that come with Snow Leopard to be rather limited).