Hi, I just tried to place an order using my American Express card, and it couldn't get past the "enter your CVV number step". I wiped the card from account and re-added it, verifying all input, and it still failed. I added one of my Mastercards, and checkout worked immediately, so it seems like something's up with Amex verification? Just an FYI...
EDIT: I just noticed that the website FAQs don't list Amex as an accepted form of payment. Provided this information is current, why would the site allow me to save Amex cards in the first place??