Sorry- and it could just be me. I couldn't get it to work.
Although I have about 30+ certifications in web dev... it's quite possible it's me.
What I do know:
• wp-content/header-images folder and filled with swf file.
• somewhat hazy on the whole "CSS header ID tag" instruction. Didn't appear to be applicable to the TwentyTen theme. I tried adding a new DIV with a new ID within the header and it still didn't work.
Maybe it's the new version of WP.