???
Please read my thread ;)
TL;DR
All SDHC, All formatted with SDformat, All with same clustersize, All with overwrite sizing, All card without issue (H2testw ok)
The issue is only with Mario Kart DS, other games work also in 8 & 4GB SDHC Cards
R4 SDHC
16GB work All
8GB don't work MK, other...