openSUSE is located at sda7, home at sda8.
The vmlinuz in /boot reads: 2.6.22.12-0.1-default and /lib/modules contains that same directory.
Here is the /boot/grub/menu.lst (I changed the title line, nothing else):

###Don't change this comment - YaST2 identifier: Original name: linux###
title openSUSE-32 10.3 (at sda7 & /home at sda8)
rootnoverify (hd0,6)
kernel /boot/vmlinuz-2.6.22.12-0.1-default
root=/dev/disk/by-id/scsi-SATA_WDC_WD1600AAJS-_WD-WCAP91531165-part7
vga=0x31a resume=/dev/sda3 splash=silent showopts
initrd /boot/initrd-2.6.22.12-0.1-default

but when I select this from the grub menu when booting, I get this error:

I had changed the title line because I have both 32-bit and 64-bit installed.

What is Error 11? And, why won't it boot? Neither the 32-bit or the 64-bit will boot.

1st, I think you must say us what kind of disks you have there.. IDE type, SCSI ?? or at least to post here one grub entry with a partition booting correctly.. At a glance I can say the problem is with:

root=/dev/by-id/scsi-SATA_WDC_WD1600AAJS-_WD-WCAP91531165-part7

It seems like opensuse writes fstab entries, don't know if it works with grub. Try change it to the default root (hd0,6).

Other thing is the line "rootnoverify (hd0,6)", I think you would delete this line, once this causes grub don't check the partition to boot and may cause troubles if your sistem turns off incorrectly.

I.E. for ide disks this entry must work well:

title whatever-you-want
root (hd0,6)
kernel /boot/vmlinuz-2.6.22.12-0.1-default root=/dev/sda7 vga=0x31a resume=/dev/sda3 splash=silent showopts elevator=as
initrd /boot/initrd-2.6.22.12-0.1-default

If your grub is installed well, just change /boot/grub/menu.lst

but if it is other type please check.

Amazing, thank you. I tweaked it a bit to add an entry for 64-bit Suse and it worked as well.

On both installations the grub entries were .../by-id/WD<long string>... that is, apparently, useless. Mepis is my main distro so adding your entry to its grub makes all work perfectly.

Thanks again.