getUserMedia error in remote desktop usage scenario

Hi all

I meet a problem, anyone has met it before?

I give presentation at meeting room, use remote desktop in windows xp(meeting room) to log into my windows 7 PC(my desk).
When I show my webrtc getUserMedia demo, it prompt “不能访问摄像头，请允许摄像头访问(can not access camera, please authorize the access to camera, which I set in noStream() callback function)”, but when I test the demo locally in my windows 7 PC, it never have problem, getUserMedia output stream to video element and play.

The Browser is chrome 22

I test several times using different remote desktop pc(win 7, win xp), getUserMedia cannot work under remote desktop environment.

Yang
Huawei