Was nearly scammed out of my mobile phone by an american bidder that bid well over the usual selling price of the phone, the seller had a good rating of nearly 100% positive feedback! After invoicing the buyer he sent a message to my email account telling me to add 30 pounds to the p&p as I would need to send the phone to his son in africa! I emailed the buyer back saying I would only send the phone once I had recieved the funds into my personel bank account, I then received an email apparently from paypal that looked genuine saying I had new funds but could not be released from paypal untill I sent a tracking number for the phone in the post!! This sounded very dodgy to me and I later recieved a message from e-bay saying that the person who owned the account who bought the phone did not authorise the bids!! So I believe they where using an innocent persons ebay account for the good rating!!
Anyway Hope this helps and be careful