NAND oob bad blocks

Hi,

I'm using 2.6.11 kernel with the MTD drivers from kernel.org. On my board, u-boot is reporting 2 bad blocks while the kernel is reporting only 1 bad block.

Looking at the MTD Nand Driver Programming Interface, it says the bad block marker only applies fo the first page in a block. However, both u-boot and the Samsung documentation(K9F1208X0B)says that either the 1st
or 2nd page of every initial block has non-FFh data at the column
address of 517.

What am I missing here or is this a case of old code/documentation?

Thanks,
Terence.