I'm so fed up with all this fake Memory stick business .......So sick and tired. It's my fault I guess, but I can't help blaming Sony for choosing a different format when they could have put an SD slot in their PSPs.... Anyway, I got myself what I thought was a good deal. A SanDisk 8GB Ultra II Memory Stick PRO Duo off Amazon for a very reasonable price. First time I mount it, I get a corrupted data reading. I format it ( trough the PSP ) and I manage to read it. I check on the memory stick menu and it tells me MG supported. Good. I proceed to transfer some games, one at the time, and after 3 - 4 games I get an unreadable memory stick again. I reformat, transfer 4 -5 games all at once. The card has been working for a week or so but then...... All of the sudden I start loosing SAVE files ! Keep making them, but then , after unlocking SOTN on DraculaX, I loose everything again ! I wanted to smash the PSP and everything in it all over the place, however, instead..... I returned the shitty Memory Stick to Amazon, and I checked for alternatives. Like original Sony memory sticks. All relatively more expensive then lexar and sandisks. Almost bought one but then I got wind that A LOT of the supposed Sony MS are merely fakes, and that it was nearly impossible to tell which store had wich.....Soooo......... I went to the official Sony store on Madison Avenue and ask them if they carried original Sony memory sticks....but before I finished the sentence I thought myself " Shit, of course they should, it's the official, original Sony store here ! "... So I asked a sales girl about an 8GB Memory stick pro duo. She ran upstairs ( in the basement there is a huge section with lots of PSPs and PS3s on display with lots of playing games , very very nice space ) and she came back with a question: "I've got here an 8GB for $44 , but also a 16GB for just a few bucks more (around $49 ) which one would you like ? ". I went for the 16GB of course, even though I've read somewhere that larger sticks could have some problems while loading games, but on the other hand I though an original Sony MS should perform reasonably well. I went home , put all of my games plus a couple of emulators on it and never looked back. I still have around 3GB free space , everything looks great and for the third time, I unlocked SOTN on Castlevania ! The moral is, when it comes to pick up a memory stick , stick to the original product and get it in a good store if you can. It ain't worth saving a few bucks online.