I have Raylight's Encoder installed which will allow me to play DVCPRO-HD Quicktimes perfectly in the Quicktime Player, but when I load the MOV's in Vegas there are some problems.
http://inventivepictures.com/redFrames.jpg
This screen grab of the timeline illustrates the issue. The red frames appear as black in the Vegas preview window. In the Quicktime Player they are properly displayed as dissolves between the previous and following clips. If I render them, they're still black.