"Excellent State" files won't recover

I'm trying to recover JPEG's from my old Smart Media card using Recuva.

I do a deep scan and recuva finds a couple of images, many unrecoverable, but some in "Excellent state".

I hit the recover button and suddenly all the files are marked as "Data error, CRC".

What's up? Why won't recuva recover files that are in "Excellent state"?

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