We have recently bought the MDK. I am only starting with it

The problem is with saving of environment with the u-boot
When rebooted, it goes to default environment.
Is it the fault with NAND, or is the problem with u-boot version.
I have not updated anything on the device, it runs the default factory u-boot.
Has anybody experiences these problems?

Here is the log:

The device carries u-boot version:
OMAP34XX LAB # version

U-Boot 1.1.4 (Mar 14 2008 - 15:08:13)

OMAP34XX LAB # printenv ipaddr
ipaddr=128.247.77.90
OMAP34XX LAB #

Ok, trying to change the address:
OMAP34XX LAB # setenv ipaddr 192.168.1.100
OMAP34XX LAB #

Checking:
OMAP34XX LAB # printenv ipaddr
ipaddr=192.168.1.100

Which is Ok
OMAP34XX LAB # saveenv
Saving Environment to NAND...
Erasing Nand...Writing to Nand... OMAP34XX LAB #, saving:

Texas Instruments X-Loader 1.41
Starting OS Bootloader...


U-Boot 1.1.4 (Mar 14 2008 - 15:08:13)

OMAP3430-GP rev 2, CPU-OPP2 L3-133MHz
OMAP3430LAB 0.1 Version + mDDR (Boot NAND)
DRAM: 128 MB
NAND:256 MiB
*** Warning - bad CRC or NAND, using default environment

In: serial
Out: serial
Err: serial
Battery levels: main 3839 mV, backup 3206 mV
USB charging started
LAN9x18 (0x92110000) detected.
Read mac address: 00:08:EE:02:50:DF
start Auto negotiation... (take ~2sec)
Auto negotiation failed
OMAP34XX LAB # printenv ipaddr
ipaddr=128.247.77.90
OMAP34XX LAB #