AmazonPayments:
I don't understand - everything on the page has a big green check. There are no SSL security warnings when you visit the site or checkout. Also, it's the same SSL we've been using since last year, and everything worked fine ... so I'm guessing that this issue you've discovered isn't the culprit. I've asked our SSL provider and webhost to view the link you sent and see what that one broken chain means ... but even the one, single broken chain icon didn't seem to invalidate the rest of the data, since everything passed.