iTunes 7 Video playback issue...
 

So I bought some movies from the iTunes store for the first time ever and double clicked them in iTunes. They started playing, but I noticed that the brightness of the videos is much higher than when I play them in Quicktime. For example, when playing a video in iTunes the blacks are almost gray, while playing it Quicktime the blacks were very dark as they should be. Why is the video playback in iTunes of lesser quality than in Quicktime? I'd like to play my movies directly in iTunes, but I also want decent playback, so now I have to revert to Quicktime all the time which isn't very convenient.

Any explanation or solution would be appreciated, thanks!

-Pieter