So... after a week of struggling, ten e-mail messages, multiple account suspensions, two sessions of faxing, and a bit of swearing, Amazon finally approved our FPS account. I have *never* seen such a poorly organized registration process.
Anyway, I got it working, and managed to process a live transaction, but there are some issues.
1. Payment with FPS fails most disgracefully if the customer did not provide their phone number on our FoxyCart checkout page.
The message was along the lines of "the following inputs are not well formed: phone number." Is it the case that the FoxyCart input for phone number is actually buggy, or is it the case that Amazon FPS requires a phone number? (I'm disabling Amazon payments until this one gets resolved.)
2. When it failed disgracefully, it left a link to follow, to the Amazon Payments page, not to our store. Is there a way to resolve this? (Not really a FoxyCart issue, but someone might know.)
3. When it fails disgracefully, the back button brings you back to an unpopulated checkout page, so that the customer gets to enter all of their information all over again. (Yuck!) Any way to prevent this? Or better, retrieve address info from the Amazon account?