Ebay provides BUYERS with a buyer protection clause. This states that if an item fails to appear, not only do they get their money back they can state whatever they want on the feedback. It is up to the SELLER to PROVE that the item actually arrived, this allows any buyer to purchase whatever they want in the knowledge that should the item have no tracking information, they can get the item AND their money.
Ebay do NOT offer any kind of similar gaurentees to SELLERS. This opens us as sellers to all sorts of fleecing, openly touted on many "How to get ebay stuff for free" forums, one of which has an extensive thread detailing how to get Skylanders merchandise for nothing. Oddly enough exactly the items I was defrauded of.
As a SELLER, it is your duty to send EVERYTHING, no matter how small, recorded delivery, and charge the ****ers over the odds for it. Lest you experience what I have.
It should be noted that the only items I have had trouble with are Skylanders items, desirable and popular. The other stuff I've sold, no matter how rare or unique have always arrived. I would name the fraudsters, however that would be churlish of me, all I'll say is look at my feedback and beware those that complain.
If you have an issue with a buyer/seller, you'll know that it is genuine if it is resolvable without involving ebay itself, but the minute the funds are "held" in your paypal account without notice, you need to start asking questions about the validity of the buyers claims.
Good luck, you will need it.