really weird quicktime issue

[catachip]

So I have a totally updated OS X Snow Leopard and quicktime, and no weird video plugins installed. For some reason (even after complete fresh installs) quicktime X will only show a black screen when I start to play a video. I can hear the audio, but the video wont play. After I wait about 20-30 seconds the video will start playing. Sometimes it starts playing the video right away, but usually it does this. It's like it's caching something maybe? I have no idea.

As I stated, it happens even after total fresh reinstalls of OS X 10.6

Anyone hear of this or have a solution?

Thanks so much!