I just finished a session of chrono trigger on snes9x, saved the state and turned the psp off by the switch. Then the psp wouldnt acknowledge there was any games/pictures or anything on the memory stick. just plugged it into usb and its corrupted as I suspected (fake 4gb card) i shouldve backed it up ages ago, but always thought it would be fine.
i've as good as accepted ill never get my chrono trigger savestates/any of my game data or homebrew back, and would be willing to try anything anyone can recconmend to receive my precious data! it still says there's 300mb free but just shows 4 files as  boxes, its as if its displaying the partition table and i cant access the files, who knows :)