PB remplacer l'image du gfxboot sur debian ?

Bonjour,

Je n'arrive plus à recreer un gfxboot sur debian sans avoir un message du type :

"invalid format" au boot :(

J'ai pourtant modifié l'image dans gimp pour qu'elle soit en 800x600 et à la bonne taille à l'octet près.

comprend pas :(

Par contre si je recupère un theme tout fait ça fonctionne. C'est donc lié à l'image que je rajoute mais je ne vois pas ou est le problème.

Voilà comment je m'y suis pris :

# mkdir /home/morphinux/gfx-boot
# cd /home/morphinux/gfx-boot
# cpio -i --preserve-modification-time < /boot/message
# <remplacement de back.jpg>
# find . | cpio -o -H newc > /boot/message

et voilà mon menu.lst :

# menu.lst - See: grub(8), info grub, update-grub(8)
#            grub-install(8), grub-floppy(8),
#            grub-md5-crypt, /usr/share/doc/grub
#            and /usr/share/doc/grub-doc/.

## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
default		0

## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout		10

# Pretty colours
color cyan/blue white/blue
gfxmenu (hd0,2)/boot/message

## password ['--md5'] passwd
# If used in the first section of a menu file, disable all interactive editing
# control (menu entry editor and command-line)  and entries protected by the
# command 'lock'
# e.g. password topsecret
#      password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
# password topsecret

#
# examples
#
# title		Windows 95/98/NT/2000
# root		(hd0,0)
# makeactive
# chainloader	+1
#
# title		Linux
# root		(hd0,1)
# kernel	/vmlinuz root=/dev/hda2 ro
#

#
# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST

### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below

## DO NOT UNCOMMENT THEM, Just edit them to your needs

## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specific kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
##      kopt_2_6_8=root=/dev/hdc1 ro
##      kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=UUID=71542543-254a-4ae6-a2ca-8fd46c8f795d ro quiet splash=silent vga=791 splash=silent

## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd0,2)

## should update-grub create alternative automagic boot options
## e.g. alternative=true
##      alternative=false
# alternative=false

## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
##      lockalternative=false
# lockalternative=false

## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=

## should update-grub lock old automagic boot options
## e.g. lockold=false
##      lockold=true
# lockold=false

## Xen hypervisor options to use with the default Xen boot option
# xenhopt=

## Xen Linux kernel options to use with the default Xen boot option
# xenkopt=console=tty0

## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
##      altoptions=(single-user) single
# altoptions=(single-user mode) single

## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
##      howmany=7
# howmany=all

## should update-grub create memtest86 boot option
## e.g. memtest86=true
##      memtest86=false
# memtest86=true

## should update-grub adjust the value of the default booted system
## can be true or false
# updatedefaultentry=false

## ## End Default Options ##

title		Debian GNU/Linux, kernel 2.6.22.7-slh-smp-1
root		(hd0,2)
kernel		/boot/vmlinuz-2.6.22.7-slh-smp-1 root=UUID=71542543-254a-4ae6-a2ca-8fd46c8f795d ro quiet splash=silent vga=791 splash=silent 
initrd		/boot/initrd.img-2.6.22.7-slh-smp-1

title		Debian GNU/Linux, kernel memtest86+
root		(hd0,2)
kernel		/boot/memtest86+.bin

### END DEBIAN AUTOMAGIC KERNELS LIST

title Windows 2K/XP/2003 (hda1)
chainloader (hd0,0)+1

title linux (hda6)
kernel (hd0,5)/boot/vmlinuz BOOT_IMAGE=linux root=/dev/hda6 acpi=on resume=/dev/hda7 splash=silent vga=788
initrd (hd0,5)/boot/initrd.img

merci d'avance pour votre aide