For some reason on Category pages parts of the navigation menu disappear. On my dev site the whole nav menu was blank. On your dev site you can see this behavior here: http://wp-cablecast.raytiley.com/?cat=992. The menu items under "Schedule" disappear.
I'm not exactly sure why this is happening, it has something to do with categories of custom post types and wp_query. See this discussion: https://wordpress.org/support/topic/wp-nav-menu-dissapears-in-category-pages-1/page/2/. The very last post has a fix that worked on my dev site.