I know it's not an MP3 player,but they use the same kind of memory,namely flash (well,most of them anyway).It was acting up,I used a recovery program to recover files from it,removed it from the card-reader,stuck it back in the camera and it says card unreadable.Stuck it back in the card-reader and it says IOCTL call error.
Isn't there any way to recover it?I mean,like an app that you guys use to recover dead players or procedure or a low-level format or something.

Have you tried wiping the connectors on your SD card to see if that helps?

I didn't try that,but I gave up.Damn... had a lot of pictures on that thing...bought a new one.Thanks for the help!