Create WM6 Emulator ROM error, please help

[dchanym]

Could big brother teach me how to re-create the emulator rom from
the dump files. I want to test customed rom before flashing to my Hermes.

I do the following steps re-create the emulator rom. But fail with following message:<

Name of rom is wm6vga.bin

Steps:
1) NBSplit -emu WM6VGA.bin
==> got both WM6VGA.bin.extra and WM6VGA.bin.payload
2) ImgfsFromNb WM6VGA.bin.payload imgfs.bin
==> got a imgfs.bin
3) imgfstodump imgfs.bin
==> got all rom files of emulator rom in "dump" directory
4) ImgfsFromDump imgfs.bin imgfs-out.bin
==> new imgfs-out.bin created
5) ImgfsToNb imgfs-out.bin WM6VGA.bin.payload WM6VGA-out.bin.payload
==> get ERROR here, see below:
================================================== ======
ImgfsToNb 2.0 RC 2
No IMGFS partition found in partition table in WM6VGA.bin.payload. Exiting.
================================================== ======

any reply is welcome.
thanks in advance