I don't know if it is just my store or not, but when I use the same email address for both my foxycart account and the Pay with Amazon Sandbox account I created, all of the previously saved foxycart information gets overwritten.
This includes my password. Even after clicking the "Forgot Password" link and entering the new password, it still fires the error message for an incorrect password even though it loads the information.
After it loads the address and payment information, it loads the last ship to address used in amazon (along with the payment information) instead of the information that was supposed to be saved to the foxycart account. Essentially, Amazon overwrites the Foxycart account.
Can users not use the same email address for both Foxycart and Amazon without their information being overwritten?
Also, I noticed that Steps 2, 4, and 5 in the cart don't populate on an Ipad while using Pay with Amazon. Hopefully this can get a patch as well.
Other than that I love the cart. Kudos to your team.