When does seller's responsibility end?

I am not endorsing PayPal, but I have several hundred (if not more) transactions with them, almost all positive. And with the few problems I have had on PayPal, I feel that the PayPal team acted fairly and timely. Making forst contact with them is a little problematic, but once an complaint is filed they are pretty good about following up. A couple of wods of advise:
1- Have all of your documentation in order regarding what you shipped or received. You DO have documentation, right?
2- Never get angry or upset with the PayPal agent, either in word or writing. They deal with angry people all day, and I assume that they just write off the jerks.

PayPal makes and receives payment via several methods, including bank cards. In the U.S. most bank cards require a no questions asked 30-day return, some are 60-days. In Europe and Asia 45 days is quite common. So while 2-7 days may seem reasonable for several of the posters above, it's not reasonable according to PayPal Ts & Cs and may not be legal. If you don't like it, don't play in PayPal's sandbox.

Rlwainwright - re: the situation with the watch. I'm just curious - did you happen to check the shipping weight of the package? It seems that it would be obvious whether the watch or an empty box was actually shipped. That would indicate whether this was a PayPal or USPS claim issue.

Agreed
Refund the money BUT Ask him to return the unit FedEx at his expense and never deal with him again.

No returns will not help. The buyer simply has to state to his CC company not as described and have them issue a chargeback. You must state selling as is somewhere in your ad.

RW. you need to have a CC tied to your account then have the CC company issue a chargeback. They make the final decision that way, not paypal. Muzikat, if you sold it on ebay, the buyer has 45 days to file a claim. What a way to imply warranty when actually there was none. Unfortunately, you must state selling as is somewhere in your ad.

The moment it ships, fully insured, packed and boxed with the original materials. Avoid paypal in future transactions, not only are their fees outrageous but they offer not protection for the seller from a dishonest buyer. Seller beware.