Hi there. I bought 2 DSi XL, one for me and another one for my partner. They were pre-installed with the same 1.4A firmware. (Australia) Then, I bought 2 identical M3i Zero cards and installed exactly the same Fcore.dat and SYSTEM file on them. It works perfectly on one of the DS, and not on the other one. This problematic DS recognises the cart and I can see the Alexrider Stormbreaker icon on it. But when I press it, it either says "no SD card found" or "no system file found! put system file in". When I take this cart and put it in the other DS, it works perfectly and I can play the game, save, etc. I just simply don't understand how this is possible with the same firmware version and same cart. Could anyone please help? Thanks.