Samsung nand flash on pxa

Hi,
I am working on 2.6.12 kernel with the latest mtdsnap shot.I have
Samsung nand chip K9F1208UoM and it is on GPIO.Nand chip is detecting and i am able to mount also. when i mount i get this error messages ,but it mounts.

BOOT messages....

NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB 3,3V 8-bit) Scanning device for bad blocks
Bad eraseblock 0 at 0x00000000
Bad eraseblock 185 at 0x002e4000
cmdlinepart partition parsing not available
Using static partition definition
Creating 2 MTD partitions on "edb7312-nand":
0x00000000-0x00800000 : "EP7312 Nand Flash"
mtd: Giving out device 4 to EP7312 Nand Flash
0x00800000-0x04000000 : "EP7312 Nand Flash"
mtd: Giving out device 5 to EP7312 Nand Flash
pxa2xx_udc: version 14-Dec-2003

Mount messages.....

#mount -t jffs2 /dev/mtdblock4 /mnt/cf/

nand_read_ecc: Failed ECC read, page 0x000000e0
nand_read_ecc: Failed ECC read, page 0x000000e0 mtd->read(0x400 bytes from 0x1c000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x00000120
nand_read_ecc: Failed ECC read, page 0x00000120 mtd->read(0x400 bytes from 0x24000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x000001c0 mtd->read(0x400 bytes from 0x38000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x000002e0
nand_read_ecc: Failed ECC read, page 0x000002e0 mtd->read(0x400 bytes from 0x5c000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x00000320
nand_read_ecc: Failed ECC read, page 0x00000320 mtd->read(0x400 bytes from 0x64000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x000003c0 mtd->read(0x400 bytes from 0x78000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x000004e0
nand_read_ecc: Failed ECC read, page 0x000004e0 mtd->read(0x400 bytes from 0x9c000) returned ECC error
nand_read_ecc: Failed ECC read, page 0x00000520
nand_read_ecc: Failed ECC read, page 0x00000520 mtd->read(0x400 bytes from 0xa4000) returned ECC error

NAND write gives me this......

./nandwrite -j -f /dev/mtd4 nand.jffs2

MTD_open
MTD_ioctl
MTD_ioctl
MTD_ioctl
Writing data to block 0
MTD_ioctl
Bad block at 0, 1 block(s) from 0 will be skippedMTD_ioctl

Writing data to block 4000
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write
MTD_write

NANDTEST gives me this

[root@Sarva /root]#./nandtest /dev/mtd4 MTD_open
MTD_ioctl
This will erase the first block of device, continue? y

Performing Flash Erase of length 16384 at offset 0...MTD_ioctl

nand_erase: Device is write protected!!!

MTD Erase failure
: Input/output errorMTD_close

[root@Sarva /root]#./nandtest /dev/mtd4 MTD_open
MTD_ioctl
This will erase the first block of device, continue? y

Performing Flash Erase of length 16384 at offset 0...MTD_ioctl

nand_erase: attempt to erase a bad block at page 0x00000000

MTD Erase failure
: Input/output errorMTD_close

After mounting if i try to write any thing it writes ,when i REBOOT the system nothing remains on the chip.Could any body give me some pointers.

Thanks in advance,
Ramprasad