No Items stay in Shopping Cart on Mobile

Hi,
Im having some problem with your marketpress plugin on mobile devices....
For some reason on a mobile device when i hit the checkout button it takes me to the checkout page but it say's - "there are no items in your cart".... This only happens on Mobile Devices....
Need to fix this problem

Need to look @ site on mobile device and

1 ----- add a product to cart
2 ----- then hit checkout

Thanks
Stephen