First off, change your cdvd plugin to CDVDnull. Then go to File->Run CD, and you will go to the bios. After a few moments, choose Browse, and then you will see the memcards. Chose any memcard, and it will ask you if you want to format it. Chose "yes" (or something like that). After that format the other memcard. Now close the emu (after it has finished), go back and change your plugin to the one you had before, and play your game.