The worst ebay/paypal experience I have had was I sold a couple of old box cameras - for a grand total of $3.

I was busy and did not ship them out right away so I sent the buyer a message saying that I would be late sending them out, and then sent her another message saying they had been posted when I sent them out. About a week later I receive negative feedback from her stating that the items never arrived, and that I wasn't responding to emails or messages.

I checked, she sent me one message less than 24hrs. earlier. She also filed a claim with paypal, but backed off when I stated that I have no responsibility for items once they're shipped and that if it was so important to her she could have asked for delivery confirmation or insurance. Technically paypal asks for sellers to provide proof that an item was sent out, but after that she called me a thief and liar and said it wasn't worth her time to fuss over $3 - so I refused to refund her any money. Eventually her complaint expired and I got the $3.

But it was really irksome to have gotten negative feedback saying I stole her money and wasn't responding to messages...

In my opinion, ebay's gone down the ****ter for sellers since they decided sellers don't have the right to give buyers negative feedback. Since they changed that I've noticed a lot of buyers have gotten pretty nasty attitudes even if they don't leave negative feedback.