I accidenally upgraded the firmware which my r4i card didn't support and so the DSi keeps showing "There is nothing inserted in the Game Card slot" or "...Press and hold the power button to turn off". So guys, please helping me how to downgrade the firmware. I have just bought this DSi 3 days ago. And i don't have enough money to buy a new r4i card, so don't ask me to do that. Thanks.