Hey, I've been using the R4 + MicroSD card for several months and I have never had any problems until today. This morning, I wanted to use the SD card to transfer music files onto my cell. So, I copied all the current DS files into a file on my computer and went ahead transfering the MP3 files. After I was done, I cleared all the music files and copied the DS files back onto the SD card. However, when I powered up my DS, it said all the files were corrupt. So then I cleared everything again, and tried to reinstall the kernel. That resulted with the top screen blacking out as I clicked the menu option on my DS. Thanks in advance !