Several of my memory cards just suddenly stopped working one day. Only one will work, and it works in both of our PS2s, but the other three won't work in either. When we put them in without a game in the machine, nothing shows up in browser. There is no memory card to even press and check, it just doesn't show up. It says 'No Data' on the screen, and never does anything more. All of them were working recently. One of them has never even really been used, it is practically brand new and we checked it as well. It was in a completely different room from the rest of them. Another one WAS submerged before, but we fixed it and it worked just fine. The last one had nothing around it to damage it as far as we can remember. Only one memory card works fine, and it has been used recently too. It was even around in the same area as a one of the others, so we're ruling out magnets or humidity. We're thinking it's not specifically a problem with the PS2 we first tried them out on, as they do the same thing in the other PS2 we have. Anyone have any idea what's going on, and possibly how to fix it?