System not booting from NAND

I repartitioned my system... so that my kernel partition is now 3MB
instead of 2MB and i have gpio and spi drivers

I also shifted the root partition so as to avoid an overlap
Now i am able to port the kernel zImage with the configurations for gpio
and spi on my system

When i boot the system from the NOR flash... ie. from the BIOS menu it
works fine
But the system does not boot at all from the NAND flash 
what could be wrong

Th only changes i have made are:
1. repartitioning as explained above
2. In linux command line in the boot parameters i changed 
 "root=/dev/mtdblock2" to "root=/dev/mtdblock3"

Apart from this everything is the same

where am i going wrng?
Also could you give me a guideline as to what you mean by "mtdblock" and
"zImage"

sorry for the newbie questions

Thanks in advance
Chinmay

The new supervivi has the more kernel partition-5M, according to the
official linux kernel, 
Another, you can use vboot in nand flash as the boot loader.
Because the old supervivi have the fixed space -2M for kernel. It 's not
easy to change it.

hi Mindee,
Thanks for the help
I will try with vboot
Also where can i get the new version of suoervivi?
is it available in the downloads section??
Chinmay