Hi,
Things to ponder about if you have not already done:

- Try using first 1 GB partition since if 2 GB Micron flash  is of
different dies and there is a single chip select ,there can be problem.Try
to recreate the problem by freshly erasing it...

- Change the nand.h file to reflect the maximum page size and oob
information macros if not already done ..

- mtd_abi.h has nand_oobinfo structure and eccpos field which has 32 length
,change it to 64 byte lenght.

rgds,
sharanu