Thanks,
Randal, your payola check's at PayPal!
My suspicions and
Edouard's thoughts are the same. After starting this thread, I created a practically empty HTML file with nothing much more than the two tags WC uses for an image and a movie. The fact that WC sees them is all it seems to take to get it to upload the latest version of each type.
I don't yet use the image file, but I probably will. I first attempted to use the QT movie with three different methods; Embed, Object, and Apple's old JavaScript. None are up-to-date methods, but HTML5 video method is not widely adopted, either!
For the movie, I finally used an iframe in the 'webcam' page with a direct Ima link to the file. I don't like I iframes any more than JavaScript, but it works.
At least on my Mac... I haven't tested it on Internet Exploder!