Why R4 not working

The R4i card currently is blocked on the Nintendo 1.4.1 firmware, this is normal. Nintendo is doing a good job at preventing you from playing illegally downloaded copies of their games.

Cards that work on the 1.4.1 firmware (genuine cards only, I don't know about clones / fakes, but they probably don't work) include the Acekard 2i, EZFlash Vi and M3i Zero

I'd recommend buying your DS cards from dscardworld.com or nds-gear.com but probably nds-gear if you live in Canada or Europe since their international shipping's a bit cheaper

you can try this offical site for the firmware kernel-

http://www.r4i-sdhc.com/