Had the same problem with a rockape1981, looked into his feedback and there were a lot of unhappy sellers complaining of non payment. Natuarally i opened an unpaid case and also wrote to ebay to complain and bring to their attention this serial offender. Of course they did nothing but advise me of opening a case. I also told them their system was flawed but i guess the current procedure is more convenient for them as they have less to do.
The problem is if sellers dont open an unpaid case then the culprit will continue to get away with it and thats the problem although obviously ebays system for highlighting offenders is flawed. The sellers who left positive feedback with negative comments should have instead opened an unpaid case rather than the comments as it ultimately does nothing to block the unsavoury time wasting buyers. Had they opened cases instead i wouldnt have had the problem, but some people dont have the time and after i wrote to one of his victims she said she was too afraid to open a case for fear of antongonising mr rockape1981.
Ebay really does nothing to assist the sellers against time wasting wankers.