A spiffy (and free)  app called Simplified Universal Player Encoder &
Recorder (SUPER) did the trick. Now I have all Puffy vids from youtube
squirrelled away on my systems.

Also a handy page (http://javimoya.com/blog/youtube_en.php) has a
webapp to isolate and download your favorite flash based vids. Then you
reencode them usign the above app.