I am writing this just to give others the advantage that I haven't in dealing with PayPal and their claims system.
If you are ever involved with a dispute or claim via PayPal in relation to non receipt or similar, the outcome seems to always be the same reagardless to your position i.e whether your the buyer or the seller.
I have had this situation arise from both sides and once the claim is logged, PayPal email you asking for any supporting infromation, such as mail tracking details of you are the seller, or correspondance details if you are the buyer. In both instances you are then sent an email saying PayPal is reveiwing this claim and if they require any further information they will contact you by x date, in all instances I have experienced you will not hear anything until that date and at which time they uphold the claim and refund in full!
I am not writing this from a sower grapes perspective as I have been on both ends of this situation but it seems that nothing is done about a claim once they have the information, it feels as if they almost diarise it for the date they have notiified you of and when that date comes around they just press a button and issue a refund regardless to the merits of the case!
What us it that to anyone? It enables someone who may have recieved an item the chances potentially of pulling a fast one and potential genuine sellers of being out of pocket, on top of this with the cut PayPal take on everything it makes me very angry the one service they are meant to provide doesn't deliver, which is a real shame! I suggest doing everything you can to sort it our via Ebay to avoid the long drawn out process that is PayPal, and in many instances save time as well as money!