The problem with the 1 gig scan disk memory stick is very real and needs to be solved by the factory. the psp and any other reader will not read the card after it has been corrupted.
I have had this problem and tried to reformat the card in every way possible. Nothing works. you cannot delete anything off the stick because once your stick is corrupted everything on your card cannot be changed thru your any other device. Whatever you try to do it will say "failed" delete failed, format failed, save failed.
I tried helping a few people with this problem and went thru all the steps and more. If anyone has anything more creative. Please help me.