"...change at YouTube is that apparently you can no longer download the videos that you yourself posted."

As McGrath says, there ARE ways to get any video. Sometimes a program will work ok, but if you figure out how to locate things in your browser cache, you can find it, move it and re-name the code word they use to confuse you. They don't want it to be simple, but as far as I know right now, it MUST be on your computer in order to play.