The items in your menu are pages instead of category pages that include posts.
You can follow the steps in this guide on how to add category pages to your custom menu: http://en.support.wordpress.com/menus/#adding-category-pages
The items in your menu are pages instead of category pages that include posts.
You can follow the steps in this guide on how to add category pages to your custom menu: http://en.support.wordpress.com/menus/#adding-category-pages