Windows 7: Video and image capture problems on windows 7 64 bits

Hello,

I want to capture screen flow in video or image on windows 7 64 bits system, with NVidia Quadro 600 graphic card (driver is up to date). I use lib vlc for video capture, or "print screen" button for image capture.
When I try to capture a fullscreen opengl application, or a QML application, or WPF application, the captured image is black. It seems that graphic card content can't be acquired...
It is the same for each computer which is under windows 7.
This manipulation worked on windows XP.

Question:
what are the changes on screen capturing between windows XP and windows 7 ?
how can I resolve this problem ?
is there any option to activate in system ?
is there any software which could work (with an API) ?

Thank you very much,

Ab28

After trying a good number of streaming video capture programs I came across RipTiger. I had a good feeling about it and it was on sale........I have yet to be disappointed. Plus it unloads the commercials.....