On my PS2, the browser sees both a PS2 card and a PS1 memory card. Do you have a non-backup PS1 game? If you turn on the PS2 with no boot disk, as I'm sure you know, you'll get the browser. It should display all working memory cards that sit in the slots. If it doesn't then the card either isn't in properly (sometimes they need a jiggle) or the card is faulty or the PS2 is fauly. You should also try this without the mod key in to get the machine back to basics. (You've probably done so). If it still doesn't work, then your kit is faulty. If it's both cards not seen, then I suggest the PS2 is looked at. If the card/cards is/are seen without the NeoKey but not with the NeoKey, then something's wrong without - I have no experience in this zone.