The only time I have had this occur was when the buyer had to re-verify his credit card. Have they asked you to do that? You really need to give PayPal a call. My buyer had made the payment, it was in my PayPal account, and PayPal called me to tell me they were investigating his account. He had a $20,000 line of credit on his card and it made no difference. It still took over a week for him to be able to pay me. And this was with both of us calling PayPal several times a day! It's sooooo frustrating to try to pay for something and not be able to. My buyer has not bought on eBay since.