I'm assuming your referring to sending it to the 'requested/alternative' address. If you send it to any address that is different to what is listed on the paypal details. You will not have any protection whatsoever, hence open to fraud.
I would advise to report the buyer to ebay as well as paypal and notify them that the member does not have a legitimate (shippable) address. From what I understand it is not possible to even register with paypal without a street address.
Perhaps the user used 'spaces' to trick the system in believing that there is an address. Not 100% sure about that, but thats the first thing that comes to mind.