Foul language aside (It was a communication misunderstanding, nothing to get hotheaded about)
What you are seeing is a "Direct Draw" Frame. There are two sections of a video card that place "frames" onto the screen. There is the "normal" part, which renders your low performance 3D and 2D images, without really cranking up the video hardware. What if an application has already done 99% of the rendering work, (Meaning it already has images ready, they just need to be on the screen for you to view) Well it would make no sense to force the video card to do mountains of unnecessary work, so Media Players use what is called the "DirectDraw" API which is a part of DivX.
Direct Draw interfaces with the "Hardware Overlay" part of your video card. A hardware overlay is a section of your video card that accepts "raw" video data. The video card does not have to do anything to the information, just display it.
The Video card essentially "blanks" the portion of the screen that the DDS (Direct Draw Surface) is rendering on top of, and pipes the video information straight to the screen. This is why when you take a screenshot of a DDS you get just Blackness. In this case, the blackness is a "null information" so the Direct draw renders on top of it.
This is easy to see if you drag a media player around while it is playing. On the first frame the media player moves, displacing the "blanked" DDS. On the next frame the video is displayed where the DDS used to be. The next frame it displays correctly. Sometime on really unstable systems you cannot move the DDS, you drag the Media player arund but the video stays on the same part of the screen...
Was that an adequate explanation?