C6748 Development Kit (LCDK), NAND question, Bad Block marks

Good afternoon!

As short description:

- the dev board is LCDK

- C6748_StarterWare_1_20_04_01

-compiling example - /C6748_StarterWare_1_20_04_01/examples/lcdkC6748/nand

Lets look at example output

************* StarterWare NAND Application ************
 ****************** NAND DEVICE INFO ******************
    MANUFACTURER ID    : 0x2C
    DEVICE ID          : 0xCC
    PAGESIZE           : 2048 Bytes
    BLK SIZE           : 131072 Bytes
    PAGES PER BLOCK    : 64
 ******************************************************

Please Enter The Block Number(0 - 4095) 10
Please Enter The Page Start Page Number(0 - 63) 0
 Please Enter The Number Of Pages To Write 1
 Erasing The Block 10                         : Succeeded.
 Writing To Page 0 Of Block 10                : Succeeded.
 Reading From Page 0 Of Block 10              : Succeeded./S-S/ /T-T/ /A-A/ /R-R/ /T-T/ /E-E/ /R-R/ /W-W/ /A-A/ /R-R/ /E-E/
 NAND Data Integrity Test                    : Passed
 ******************************************************
 Block Is Bad, Can't Continue ...!!!

A little modification at the end of this file by adding one more check for bad blocks

retVal = NANDBadBlockCheck ( &nandInfo, blkNum );

UARTprintf("NANDBadBlockCheck(). rc=%01d",retVal);
          if ( retVal == NAND_BLOCK_BAD )
            {
              UARTPuts ( "\r\n Block Is Bad, Can't Continue ...!!! ",-1 );
              while ( 1 );
            }

If the application writes any data from page 2 to 62, everything is good.

The question is, when any data writes to any blocks at page 0 or 1 entire block becomes bad, so why it happens and how to fix it?

Thanks in advance!

WBR,

Dmitriy.