OK you have supplied all the info we asked, I saw them posted, but it takes a bit of guessing here still unless you also show us some additional output from:
ls -l /dev/disk/by-id/
This additional info became necessary since your
menu.lst
shows your SuSE 11.4 was addressed by root=/dev/disk/by-id/ata-WDC_WD1600BEVT-22A23T0_WD-WXD1A60S3045-part6 instead of /dev/sda6. I can make assumption logically that they are the same for now, if you found out that they are not the same, then you need to change accordingly.
Assuming root=/dev/disk/by-id/ata-WDC_WD1600BEVT-22A23T0_WD-WXD1A60S3045-part6 is /dev/sda6 and also that /dev/disk/by-id/ata-WDC_WD1600BEVT-22A23T0_WD-WXD1A60S3045-part8 is /dev/sda8
Then I think all you need to do is have your menu.lst file changed following entirely as follows:
linux-h5jv:/home/philippe # cat /boot/grub/menu.lst
# Modified by YaST2. Last modification on jeu. avril 14 00:32:27 AST 2011
# THIS FILE WILL BE PARTIALLY OVERWRITTEN by perl-Bootloader
# Configure custom boot parameters for updated kernels in /etc/sysconfig/bootloader
default 0
timeout 8
##YaST - generic_mbr
gfxmenu (hd0,5)/boot/message
##YaST - activate
###Don't change this comment - YaST2 identifier: Original name: linux###
title openSUSE 11.4
root (hd0,5)
kernel /boot/vmlinuz-2.6.37.1-1.2-default root=/dev/disk/by-id/ata-WDC_WD1600BEVT-22A23T0_WD-WXD1A60S3045-part6 resume=/dev/disk/by-id/ata-WDC_WD1600BEVT-22A23T0_WD-WXD1A60S3045-part8 splash=silent quiet showopts vga=0x314
initrd /boot/initrd-2.6.37.1-1.2-default
###Don't change this comment - YaST2 identifier: Original name: failsafe###
title Failsafe -- openSUSE 11.4
root (hd0,5)
kernel /boot/vmlinuz-2.6.37.1-1.2-default root=/dev/disk/by-id/ata-WDC_WD1600BEVT-22A23T0_WD-WXD1A60S3045-part6 showopts apm=off noresume nosmp maxcpus=0 edd=off powersaved=off nohz=off highres=off processor.max_cstate=1 nomodeset x11failsafe vga=0x314
initrd /boot/initrd-2.6.37.1-1.2-default
###Don't change this comment - YaST2 identifier: Original name: other###
title gnome 3
root (hd0,8)
kernel /boot/vmlinuz-2.6.37.1-1.2-default root=/dev/sda9 splash=silent quiet showopts vga=0x314
initrd /boot/initrd-2.6.37.1-1.2-default
That changed last menu item should let you boot up to genome in /dev/sda9 partition.
I did not change the 1st 2 menu items.
If this worked, then you can modify it further to include some resume partition specifications, and duplicate another FAILSAFE menu item for genome. However these are attempts only piratical after you got the 3rd menu item working first.
BACKUP your menu.lst file before you edit. Then you are safe.
sudo cp /boot/grub/menu.lst /boot/grub/menu.lst.bak
Thing to note is I found that your post menu.lst actually chained you to boot in another instant of GRUB. That means you will get 2 separated GRUB menus and can be confusing. What I proposed was just using the currently working 1st booted copy of GRUB. You will be better off using just one, and can add as many items in menu as necessary. When one Linux installation totally unaware of another, they each install own GRUB, and may ZAP away each other in subsequent auto-update or system maintenance works. When that happened, you suddenly lost a bootable Linux. MBR, stage1 stage2 etc can get ZAPPED. Best to back them up.
sudo dd if=/dev/sda of=/media/USB/my-MBR.bak count=1
It is an example to backup MBR in a USB thumb drive mounted at /media/USB/
When you got ZAPPED, you can put back your backup MBR:
sudo dd of=/dev/sda if=/media/USB/my-MBR.bak count=1

I still don’t understand why you need to install this way though, if all you want is to have Gnome & KDE environments they can be together installed side by side on the same partition, and same instant of Linux, instead of separate. Unless you install different application, different kernel and have different set of users, etc, or you prefer to have 2 installation just for extra robust, in case one copy of Linux got messed up. When you use YAST to install software you can actually add genome to originally KDE copy of suse or add KDE to originally genome desktop. You can select at login menu to have KDE or genome of any other desktop managers like ice or xfce or enlightenment… there are many, if you want them all 