Amazon Checkout Issues

Hello!

We have a “checkout with Amazon” option on our site. The problem is that Amazon only has two options on their end for shipping:

Fixed weight by item and

Fixed cost.

Our shipping on the site is calculated by weight and other things of the sort, which doesn't match with either of these options.

My question is…does anyone else have problems with Amazon checkout not matching up with your CS Cart checkout? I'm not sure how to get Amazon to recognize our shipping upon checkout.

Thanks!