Since the release of the PSP there has been a huge influx of bootleg MS Pro cards flooding eBay. Please be aware that many of the cards being sold could be fakes and will most likely not have the capacity they say they do or will break not too long after you start using them. Before you buy a MS Pro card from eBay please read the following guide and use some common sense.
http://reviews.ebay.com/FAKE-Sony-Memory-Stick-Pro-Duo-MagicGate-Cards-Exposed_W0QQugidZ10000000001236041In the end I would say dont risk it and pay the extra 10-20 bucks and buy from somewhere like amazon.com or buy.com .
These fake cards will not work correctly in the OSD, R2, R2+, PSP or anywhere else.