Weird problem, showing in IE but not in Firefox

[garrettheel]

I'm having a really weird problem with some menu items in a custom theme I've made for prestashop. Basically, I have the following code in place to put all of the main categories into the menu:

                    {foreach from=$cat.children item=category}
{$category.name}
                   {/foreach}

This works fine in IE and displays everything correctly, but in Firefox, it doesn't seem to work.

Here's a live URL - http://shop.unisence.no/

Anyone able to help please?