How to make the Products Filter function appear in Marketpress

I think I am wrapping my head around Marketpress for the most part, but am running into a problem with the mp_products_filter function to display correctly on custom files. I have put mp_productlist.php in my theme and it works fine with the mp_list_products function. However, the mp_products_filter function is not seeming to display at all.

My code for the page is very simple:

<?php get_header();  ?>

<?php mp_products_filter();  ?>
<?php mp_list_products(); ?>

<?php get_footer(); ?>

I have deleted and added back the functions to test I was on the correct file.

When I use the virtual products file the mp_products_filter seems to appear fine with the drop down menu and "order by" drop downs. But I want to put these on my own custom file. I have attached a screenshot to show it works fine when I pull my mp_productlist.php file from my theme.

Any thoughts?