It may be well worth your time to check out the new Scrivener screencast by Don McAllister at:
http://www.youtube.com/watch?v=-DthBJhBrYs
It's a worthwhile investment of thirty-five minutes (or less because you can skip the parts you know).  You get the chapter breaks if you go to his site to download:
http://www.screencastsonline.com/index_files/SCO0275-scrivener.php
I ended up buying Scrivener because of the screencast.