thx 4 ur 'helpful' advise, ninja.
anyway i've never heard of mp3man is it like a new brand? btw mine is 512mb too and it seem the bigger the memory is the more fragile it is 
Dude, what did you expect me to say?
"Um gee, I'm sorry, you can unscrew the back, de-solder the connections, run down to your nearest electronic parts dealer, buy a new memory card, install the new memory, and download a version of the firmware and you're good to go!"
Honestly, you're better off, if the thing is still in warranty, seeing if you can RMA the thing and get a new one.