am335x u-boot <<No NAND device found>>

Hi, all,

[1]
I am working with AM335x. It boots from sd card properly and runs Linux OS fine.

[2]
As a next step I want to burn VxWorks bootrom into NAND flash (as it is described in
[ti_am335x_evm/target.ref] of Wind River Systems, Inc) which will run then automatically.

I try to perform following set of U-Boot instructions:

tftp 0x87C00000 bootrom.bin
nand erase 0x0 $(ROM_SIZE)
nandecc hw 2
nand write.i 0x87C00000 0x0 $(ROM_SIZE)

[3] However, "nand erase" command says:

>>> U-Boot# nand erase 0x0 0x60000
>>> no devices available

Also I see that at the "U-Boot SPL " starting there is a message:
<<No NAND device found!!!>> (see Appendix 1)

[4]
The switches(SW3 ,SW8) are as on Appendix 2.

NAND related env vars are in Appendix 3.

[5]
Whether anybody knows what can be a reason why the NAND is not found?

Thanks,
Yan

=======================================================
Appendix 1:

CCCCCCCC
U-Boot SPL 2011.09 (Apr 08 2012 - 18:29:14)
Texas Instruments Revision detection unimplemented
OMAP SD/MMC: 0
reading u-boot.img
reading u-boot.img

U-Boot 2011.09 (Apr 08 2012 - 18:25:03)

I2C: ready
DRAM: 256 MiB
WARNING: Caches not enabled
Found a daughter card connected
NAND: HW ECC Hamming Code selected
No NAND device found!!!
0 MiB
MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1
*** Warning - readenv() failed, using default environment

Net: cpsw
Hit any key to stop autoboot: 0

=======================================================
Appendix 2:

Switch SW3 Function (SYSBOOT[0,7], Boot mode select) (on - 1, off - 0)
-----------------------------------------------------------------------
BOOT MODE         | Setting [1 2 3 4 5 6 7
-------------------    -|------     ---|----------------------------------------
nand Flash boot |                 | 0 1 0 0 1 0 0

-----------------------------------------------------------------------
Switch SW8 Function (profile selection)(on - 1, off - 0, don't care - x)
--------------------------------------------
profile selection | Setting [1 2 3 4]
--------------------|--------- -------------
profile 0 | 0 0 0 0
--------------------------------------------

=======================================================
Appendix 3:

nand_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${nand_root} noinitrd rootfstype=${nand_root_fs_type} ip=${ip_method}
nand_boot=echo Booting from nand ...; run nand_args; nandecc hw 2; nand read.i ${kloadaddr} ${nand_src_addr} ${nand_img_siz}; bootm ${kloadaddr}
nand_img_siz=0x500000
nand_root=ubi0:rootfs rw ubi.mtd=7,2048
nand_root_fs_type=ubifs rootwait=1
nand_src_addr=0x280000