fail, did you push it far enough to where it clicks? if it doesnt click into place smoothly then you really should bring it back and exchange it for another
First: blow out any dust and check for anything stuck in the memory card slot. Second: check to make sure the memory card is intact and not damaged or broken. Third: make SURE you are putting the card in correctly. I say this because a PSP1000 and 2000 have different ways of inserting the memory card - so it is worth double checking to make sure you are putting yours in the right way.