Ustream broadcast window recognizes my camera and audio inputs, but no image. Why?

Edit Subject

I have a Sony camera running through a video converter. The converter is outputting analog. the drop down menus on the broadcast window claim they recognize the video input, but there is simply no image. Other programs on the computer recognize the camera, and this setup had worked reliably in the past; one morning it simply stopped working. No other video programs are using the camera input. I don't know what the problem is. Any help would be greatly appreciated.