Webcam Microsoft Livecam studio is "occupied"

Hello,

My new webcam Microsoft Livecam Studio works perfectly with all programms. But if I start presenter- video express 11 I get the message: "Your webcam is busy or it is not functioning. Try closing other application that might be using the webcam and select it again."

But there is no application using the webcam, no programm is working .

I later can record a video with the webcam and video express and the project even shows the presentation and I can use all the features to edit, but not at the very beginning ( for instance to select my face before recording.)

Any hint?

Thanks in Advance