One of my custom post types is unsearchable

Hi,

I created several custom post types with CustomPress. All are set to "public" settings (with "publicly queryable" set to true and "exclude from search" set to false) but only one, "edu" is always excluded from search.

I just tested it with a search plugin set to limit its search to just "edu" posts, and I still get "No posts match your criteria" every time. There are lots of posts in edu that should be showing up as search results. Is there some other setting I'm missing?

The site is http://www.henrysheldonmuseum.org

The unsearchable posts are all listed under
http://www.henrysheldonmuseum.org/education

Thanks.