thanks antoine - by the way, i made a comment in a different thread about implementing a quick-and-easy "terms of sale" page that the buyer can send a request for an invoice through... there would be a terms of service on the page that the seller would agree to when sending his payment info. a copy - filled out with both peoples information - would be emailed to both parties.
then if things like this happen the disgruntled party can present the document to authorities and have at least some form of written contract... that makes it WAY easier to pursue legal action if things go south, and is the reason that cops will chase down ebay fraudsters but not on private forums.
PM me if you want more details, i know some web based coding so i might be able to give you a hand with writing it if you want.