I have a Memory Stick Pro Duo and after attempting to delete the largest file from a Mac the stick has become unusable. I can almost access it. When I put it in my PC I can open/delete/copy/paste/rename/modify one file/folder, then it can't detect the card. If I reinsert the card I can move on to the next file, but this is really annoying and my PSP won't read it at all. The memory card access light will flash for a really long time before it says that every file is corrupted. When I have tried to format it with either the PC, PSP, or a camera that uses a memory stick pro duo, it fails. I've tried with all the different options on windows, I tried formatting it through CMD, but nothing I have tried works. Should I copy every file off one by one or is there a way to fix it?