I have installed the kernel, and loaded ext4 module.
I format a sdcard with ext4, but when I try to mount I get an error:
mount -t ext4 /dev/mmcblk1p1 /min
mount: mounting /dev/mmcblk1p1 on /min failed: Invalid argument
If I use the usbcable it mount ok

So it's looks like its something wrong with the ext4.ko module