AARGH i'm getting the same problem. just that i tried using SD Formatter 2.0 which didn't work... it says my microSD is write protected :\
i think my card is dead... T__T
I have another card issue. One of my Kingston 1GB cards works just fine in Windows, formats, reads, writes, no bad sectors on a scan. Yet, when I use it in my M3 Simply, it periodically will give an error in the game like, "Cannot read data. Power off and try again." Some games work fine, some games give the error.
I've seen it on a number of games, My Sims, Animal Crossing, etc. On this one card, it will put up a screen with the game's artwork style, saying it cannot load. I tried the card in two different DSes/Simplies, same thing. It's not the ARM7 deal, as just copying the file to a different microSD works fine. All I have been able to deduce is it's some kind of problem on writing. One a file starts with this error, it will always do it. But most of the files on it work just fine. I guess there's a few bad bits in there somewhere. I just didn't think it would wear out in under 6 months.
