i guess you using the old kernel because the NDS mode.idk, maybe space on the SD or something. Both can have a maximum of 2GB (but practically only 1GB).
but you know that the ez iv supports 32GB cards since 1.74
i would upgrade the ez iv, (the new kernels with automatically patching are awesome, but stay in the 2.01 because the newer ones are still kite a mess)
and use the supercard for the gbafs thing