QuickTime gamma shifts with H.264 HD files

Hi,

I experience some odd gamma shifts while playing full 1080p full HD content. During playback the video suddenly gets lighter and after a few moments switches back to normal / darker light.

This happens while playing videos in Lion QuickTime 10.1 (dunno about earlier versions) and also Lions iTunes 10.4 64bit. The videos play fine in other players like VLC and even on Apple TV 2.

I will provide any additional info to this bug if required. As of now I don't have any solution on how to avoid this bug.

The bug happens on 13 different well known systems (tried in 3 different households and an apple store).