I won an auction friday night and tried to pay with my credit card through Paypal and wasnt able to, some message about the transaction not being completed. I called them and they said that they hadnt been having any problems but that the payment wasnt showing up; called my CC company and the payment was pending so yes, they're having issues even if they say they're not. Contact the seller and tell them what's going on.
You need to keep an eye on your credit card statement. This happened to me once and I was charged 3 times for the same item on Paypal (and it only showed up paid as once). I immediately had to contact my CC company and do a chargeback for the multiple charges. You might want to call them and make sure it didn't go through 3 times.