Forum:"Media in category" heading not appearing in categories

I'm one of the administrator's at the Last Exile wiki. I thought that it would be cool to put all the promotional artwork and other images around the site into different categories. Someone could click on the Promotion Art category and quickly browse the thumbnails of images. But it doesn't seem to be working.

For reference, I wanted something like the LEGO wiki's Parts page. It's got a heading called Media in category "Parts" and you can see little thumbnails of everything. What I get, however, is a category that links to pages, not media, beginning with "File:" like this. Any help is appreciated. Thanks. TheBelgianGuy 21:47, June 23, 2011 (UTC)