CustomPress Archive Template

Hi guys.

I have created a Custom Post type with Custom Press called 'film_projects'.

I have created an Archive Template for film projects called 'archive-film_projects.php' to display those posts.

But that file is being totally ignored. At the moment I had to edit index.php to edit the archive layout for that post type. I haven't worked on the single post layout yet.

But it's starting to become a mission because I need to add more post types real soon..

Any help would be appreciated.

Thanks.