I can successfully record a live stream from a webcam. However, when I right-click on the Flash component that is broadcasting my webcam, click on Settings -> Video -> and then change the webcam source to a different one plugged in to my laptop, the live stream video freezes, although I can still hear the audio. If I switch back to the original webcam that I used to start the live stream, the stream goes back to normal.

The live stream will work with any connected webcam that I choose to start with. But it is once I switch to an alternate webcam source that the live stream freezes.