IF eraseall will destryed(phys) the nand flash ?

[shadow]

Hi all,
I got an Input/Output error when I erase the nand flash. It printed these 
messages.
-------------------------
Erasinand_erase: attempt to erase a bad block at page 0x00000020
ng 8 Kibyte @ 4000 --  0 % complete.
eraseall: /dev/mtd/6: Mnand_erase: attempt to erase a bad block at page 
0x00000030
TD Erase failure: Input/output error
Erasing 8 Kibyte @ 6000 --  1 % complete.
eraseall: /dev/mtd/6: Mnand_erase: attempt to erase a bad block at page 
0x00000040
TD Erase failure: Input/output error
Erasing 8 Kibyte @ 8000 --  1 % complete.
eraseall: /dev/mtd/6: MTD Erase failure: Input/output error
Erased 2048 Kibyte @ 0 -- 100% complete. 
-----------------------------

I found the Input/output error always occurred at the same page even if it 
is a new SMC. But I have a question, the block_size is larger than 
page_size, isn't it ? IF larger why nand driver attempt to erase a bad 
block at page 0x00000020. In my mind, I think one block includes many 
      ^^
pages. Another problem is why the new SMC has some bad blocks and occurred 
at the same page with using eraseall program erase it. Then I put this SMC 
that has bad blocks into Digital Camera that can erase data on the SMC. 
The DC Can't format it, what's up ? eraseall destroyed it ?

IF the SMC has some bad blocks, then how to correct it ?

thanks in advance,

Brian