Per Paypal's site regarding items not purchased through ebay:
The PayPal Buyer Complaint Policy is similar to PayPal Buyer Protection in that it enables buyers to file Disputes for Items Not Received (INR), or for items that are Significantly Not as Described (SNAD). By filing a Dispute, you can communicate with the seller and attempt to resolve the problem. If you are unable to resolve the problem, you may escalate an Item Not Received (INR) Dispute to a Claim – but you may not escalate a Significantly Not as Described Dispute to a Claim.You may not file a dispute for a Personal Payment.
Not sure how the international factor will impact this process. And of course as was already suggested, if a credit card was used to fund the paypal payment, a buyer still has full recourse by disputing the charge with the credit card company.
Greg