Trouble programming NAND flash on AM3505, with Flash Tool 1.6

We're developing a new AM3505 board that's a close derivative of the AM3517EVM eval board.  Until now, we've booted our board from an SD card, and that works fine.

Now, we're attempting, without success, to program the NAND device and boot from that.  Our NAND device (MT29F16G08AJADAWP) is 16 Gbit, 8-bits wide, and supports ONFI.  For NAND programming, we're using the TI Flash Tool 1.6.

For the flash tool configuration, we started with the AM3517EVM config file, changed only the DRAM parameters to match our DRAM hardware, and selected 'ONFI Compliant NAND'.  The DRAM parameters we believe are good, since they're the same as we use successfully in the EMIF4 setup in u-boot.

Here is the tail end of the log from the tool, with the -rxtx_trace flag turned on.

  » Waiting for 2nd
    00454-003-TX ACK
    00562-004-RX: 12 raw bytes: 05 01 05 01 34 30 07 58 13 02 01 00 '????40?X????'
  » Unknown status message '????40?X????' during peripheral boot (waiting for 2nd)

Can anyone point us to the problem area?

The full log is below.

Thanks,
Ron

----- Full log from flash tool follows -----
C:\Program Files\Texas Instruments\Flash v1.6>OMAPFlash @ temp_script.txt
 
» OMAPFlash v4.2 (Jun 24 2011)
 
»     -v
»     -stdout
»     -omap 3
»     -no_force_package_alignment
»     -rxtx_trace
»     -t 60
»     -p CUSTOM_AM35XX_BOARD
»     -2
»     chip_download NAND1BITBOOT C:\nand\MLO.idm
» Leaving parameter file:temp_script.txt
» @ temp_script.txt
» Looking for device (omap usb)
» Please turn on device
» Waiting for device (omap usb)
» Found device (omap usb)
» Awaiting ASIC id
» AsicId items 05
» AsicId id             01 05  01  34 30 07 58
» AsicId secure_mode    13 02  01  00
» AsicId public_id      12 15  01  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
» AsicId root_key_hash  14 15  01  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
» AsicId checksum       15 09  01  59 DB 63 8B 00 00 00 00
 
  00130-000-TX 4 raw bytes: 02 00 03 F0 '????'
» Searching 2nd for: CUSTOM_AM35XX_BOARD 343007 58 GP
» Loading second file Targets\2nd-Downloaders\dnld_startup_omap3_gp_8g.2nd
» Entering parameter file:omapflash2nd.txt at line: 8
»     -pheriphalboot_reopen
» Reading board configuration file Targets\Configurations\configuration_idm_8g.txt
» Reading definition file .\targets\definitions\definitions_omap3.txt
»     -board_config Targets\Configurations\configuration_idm_8g.txt
» Leaving parameter file:omapflash2nd.txt
» Sending size of second file (0x00006804 bytes)
 
  00130-001-TX 4 raw bytes: 04 68 00 00 '?h??'
» Transferring second file to target (0x6804 bytes)
 
  00130-002-TX 26628 raw bytes: 00 00 0F E1 1F 00 C0 E3 13 00 80 E3 C0 00 80 E3 '????????????????' ...
» Closing boot connection
» Waiting for device (omap usb)
» Found device (omap usb)
» Waiting for 2nd
  00454-003-TX ACK
 
  00562-004-RX: 12 raw bytes: 05 01 05 01 34 30 07 58 13 02 01 00 '????40?X????'
» Unknown status message '????40?X????' during peripheral boot (waiting for 2nd)