I'm using a 8gb Sandisk MicroSD and a SD adaptor, it worked just fine for quite some time, but in the last few days, every now and then, when I open my 3DS, it says there's no SD card (and I lose every progress if I was playing a game). I turn off the 3DS, remove and insert the SD again. Is this a known issue? Maybe it's a microSD compatibility problem? Formatting it will do any good? Thanks!