Directory plugin...some functions not working

I've activated Directory and have created categories and have added a listing to one of the categories. However, even after publishing the listing I am getting blank pages when I click on the listing and the category headings on the pages where I created listing categories.



if you click on the following link to see where I've added a button to "Add listings", you see that the listing form opens and works, but then once a listing is submitted and published, it doesn't appear on the site anywhere.