Paypal is ok for the most part. However too many people think Ebay is like overstock.com and can return anything at anytime. When you won't accept the return...they file a "not as described" on you and paypal forces you to take the stuff back.
If the person uses a bank account or paypal funds to pay for a purchase...they only have 45 days to make a complaint. However if they used a credit card company....they have as much as a year.
Paypal and Ebay is all about the buyer and could care less about the seller.