Not able to process saved shopping cart

-- url of the page with the problem -- : salsashoes.com.au/
-- HikaShop version -- : Essential 2.2.3
-- Joomla version -- :2.5.17
-- PHP version -- : x.x.x
Hi,
I managed to create a tab for my account where users can see their details and manage their carts. However, it seems that the carts can be created and saved but not have the ability to be processed and paid. In other words, I can create a cart for some products save it, then close browser and reopen my account but not be able to pay for the product in the cart at later times.
Any help will be much appreciated.
Regards.

Hi,
I just tested it and it seemed to be ok, I just saved 2 different carts, selected one, and used the "proceed to checkout" button of your cart module through your product listing page.