The reason is, that the only way to do the firmware update is to run an .nds file off the flash card.luka said:you need an old ds to update or you can use 3ds already updated?
The update instructions of r4i sdhc says:
QUOTEYou can not upgrade N3DS Card with N3DS V2.0.0. If your N3DS console has already been upgraded to N3DS V2.0.0, you will need another NDSL or NDSi or N3DS(which should be under version V2.0.0) to upgrade your 3DS flash card.
You just had to be as patient as me