main image not showing

Im using the WP ecommerce plugin to add products to a friends site but I cant seem to get the main product image to show.
I added the Product image as a ‘featured image’ widget on ‘Products – add new’ and it adds the thumbnail on the main page…http://www.memorymedia.co.za
but when you click on the image and go to the products page the larger image doesnt show up….
http://www.memorymedia.co.za/products-page/product-category/swivel-flash-drives/

What am I doing wrong? Please, any help will be appreciated!

http://wordpress.org/plugins/wp-e-commerce/