It's nothing to do with the companies but the way the video card works.
It uses video overlay, which means that the image is added into the outgoing video signal (in the video buffer) rather than in the video memory.
Windows screenshot works by taking a copy of the video memory ... which the video picture hasn't been added to yet!
Try it with anything that works through media player or your DVD playing software and you'll get the same result.
All you need is a snapshot program that can see the video buffer and you can take screenshots.
HyperSnap-DX:
http://www.hyperionics.com/hsdx/ SolidCapture:
http://www.solidcapture.com/