The card is not corrupt it's just the wrong format.
I'm not sure which it has to be but most homebrew deviced require FAT/FAT16
It's an easy fix. Just plug the card into your PC like you normally would. Right click the drive in 'My Computer' and click 'Format...'
You will get a little dialog box that pops up. The first change you will want to make is where it says 'File System'. It will have a pull down box and you can select the corect format from there.
At the bottom there is a box that says 'Quick Format'. Make sure this is NOT checked. Once all is said and done it should work for you.
BTW these are windows XP instructions. If you are using a different OS post up what you have and I'll see what I can do.
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