bschillace on "Problem with featured images in theme Twenty Ten"

Hello! I am using the theme Twenty Ten, which is lovely. It allows you to have a custom header--and I do. It also should allow for custom page headers, featured images that differ from the main page image. But for some reason, featured images for headers will only display on 2 of the 7 pages of my blog. I have followed the same steps, chosen featured image, updated, made sure all the page details were the same--but regardless, the featured header image appears only twice. Please advise! My blog is bschillace.wordpress.com.
Thank you!