Defective flash card?

When i go to save something on my 1k, it says directory error, if i take out that card and try another, it saves fine, it only does it on one of my flash cards, maybe its defective? Things i saved previously on it load up fine, i just cant save on that card.

You should backup everything on the card then format it in the MPC and try saving again.

someone wrote about using spaces in names...that is, DON'T use them. can't attest to it, but it's worth a try.