I found an acceptable replacement webcam on my second try. The first one was a Creative Live Cam Optia AF. It was unsuitable due to poor image quality and poor software. It went back to Fry's the next day. The final choice was a Logitech Quickcam Pro 9000, which does wonderfully, especially with Skype. There isn't much of an improvement when using it with apps like Yahoo Messenger, since it transmits in such a low quality, if it transmits at all.
I no longer have random crashes with Pinnacle Studio 12.1 when the cam is attached to the computer. However, Studio will crash with a corrupt stack when recording from the cam. But I think that's more of a bug in Studio than a problem with the webcam this time.