I've had troubles paying with my SPG Amex on Paypal for eBay wins. I've never charged as much as you guys charge on eBay/Paypal - but I've been denied with cheaper charges - like 10 bucks or 20 bucks. I've switched to my Chase Visa on PayPal now - which kind of pisses me off because I want to use my Amex - but Amex won't let me.