In my experience, some peeps don't understand the system. I bought an item from a newbie in Ireland. I payed in good time, he sent the goods in good time.
Few weeks later, he "neutralled" me. I wasn't best pleased

After counting to 10 and resisting the urge to flame him, I looked at his feedback. He'd done the same to a load of buyers

So I mailed him (very politely), stuck a few links to ebay help and a very bad seller who'd shafted me and waited. Lo & behold, a very apologetic reply explaining how he'd not understood and he put covering remarks under all his neutral fbs.
Both parties finished up happy

Rob