I face a little problem with categories pages.
http://saintpierre.delareunion.net/agenda/categorie/sports (agenda stands for events and categorie for category)
When debugging that page, I’ve inspected the $wp_query. And in this variable, I saw that the page is a custom taxonomy archive (is_tax => 1) and a post_type_archive (is_post_type_archive => 1).
This is impossible ! I don’t where is the bug in the code, but either the page is a custom taxonomy page (I think it should be that), either the page is a post type archive (I don’t think so, event’s list is post type archive).
I noticed that when setting my breadcrumb plugin.