you do realise just coping the files to the SD card doesnt udpate the card right?
you have to run a update once the card has loaded before you update the console
what happened is that I updated the system(3ds) before updated the card, I did that but now it says " there's nothing plugged into the gameslot"
I have that green R4i card. and the firmware they have currently from the site is, for some reason, a brick firmware. before i upgraded one of mine (i have two), they were sporting the Prince Caspian icon. when i flashed one card using the one from their site, after successfully updating the card doesn't appear anymore, like there's no card inserted. this holds true for the 3DS, DSiXL, and DSphat.
there is a way to save this, but you'll need an old firmware, and you'll probably need to try it a couple of times (downgrading firmwares doesn't always stick, it seems), but keep trying. i've done it on mine, so i see no reason why you couldn't do it on yours. i'll see if i can upload the old firmware i have (Prince Caspian, from December 2011). i hope i don't break rules by doing so, but just scratch the link if it's unsafe.
EDIT: i forgot to tell you, you'll need another flashcart that works on whatever DS console you have at hand. you'll need to run the updater from that working flashcart, but when it prompts you to press A, you'll have to swap the cart with the bricked cart. do note that on a DSi, sometimes the status gets stuck on a certain percentage, you'll have to switch to a different firmware, flash that, and then downgrade that. also, after a while, my DSphat is giving me problems by being an ass and "shorting" out whenever i swap cartridges. maybe that's an isolated issue on mine, but just a heads-up. preferably, you have a DSphat and/or a DSlite at hand to do the flashing. keep the original filenames, and keep them at the card's root.
Prince Caspian firmware (works on DSi 1.43 and 3DS 4.0.0-6, i think.