Category menu item not working correctly

-- url of the page with the problem -- : surrealrealities.com/websites/compuchild...t=listing&Itemid=469
-- HikaShop version -- : 2.6
-- Joomla version -- : 3.4.7
-- PHP version -- : 5.4.45
-- Browser(s) name and version -- : Firefox
-- Error-message(debug-mod must be tuned on) -- : None

I am migrating a site from Joomla 2.5.28 to 3.4.7. In the process I have also upgraded to HikaShop Business 2.6. Since the store and its products were already created, I hoped the update process would be painless and for the most part it is. I set up a main menu hikashop category listing but when I click on a category image, the products are displayed but there is a black band across the bottom of the image and the product cannot be selected. If I select a product from the category menu in the left sidebar, I can select the product. How can I get the main menu category listing to work?