I recently bought an R4 DS off Amazon and a Micro SD card (Kingston) 2gb off Amazon as well. When I put the Micro SD in the Micro SD USB reader, and that into the computer, it loads up it's little thing and says "your new hardware is ready to use". Then I double click on the new drive in the "My Computer" but it says "Please insert a disk into drive F" like i don't already have a MicroSD in the reader in the computer. Now, I know the Micro SD memory card works because I've been able to put that into the SD adapter and that into an old mp3 player, and connect it to the pc, but the Micro SD card to the Micro SD reader (that came with the R4 DS) doesn't seem to work. My brother suggested that it could be compatibility issues: like Kingston cards don't go with that reader. What do you think the issue is? The reader does light up when connected and it seems to be recognized with the computer, it just doesn't recognize that I have a micro SD inside it. Is Kingston at fault or something else? Help please. Thanks.