I had the same problem with my 16gb Class 10. I think I created the problem myself by formatting the card improperly with my PC. I let it choose the default cluster size, when in reality I should've chosen the largest cluster size. I don't quite remember the choices, but I believe that the default cluster size was 2k or 4k, and I fixed the problem by formatting with 16k or 32k.
I don't have any technical information about why this worked for me, but it did. I'd recommend you google for more information before trying this.
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Yes. I'm OLD.