Just a quick note on a situation where a ghost image of an SuSE 9.3
installation on Sata disk was restore to an older PC with IDE disk. As
expect it did not boot, but using the recovery simple console from the
CD 1, the grub was restored, with the usual set of:

mkdir temp
mount -t ext3 /dev/hda3 temp ( in this case the / )
chroot temp
mount -t ext3 /dev/hda1 boot
vi /boot/grub/device.map (change sda's to hda's)
grub-install hd0

also changing sda's to hda's on /etc/fstab /etc/mtab

the next time the system booted, and after a while stoped with an
error about not finding something "sda3"
ah! there is somewhere else another file with disk information? so the
cache system related to /etc/blkid.tab was the best match to this, all
pointed to it. But no results. Whatever, it would boot and stop about
not finding sda3.

SuSE 9.3 has a good collection of GUI auto recovery options on CD1.
So it was run. All right.
Those recovery options found a bootable MBR grub, so did not changed
it.
Please do change it on the GUI recovery options, rebuild it.
That was the problem.
Would like to understand why since all references to sda3 where
changed to hda3 and the grub rebuild by grub-install hd0 but the fact
is somewhere on the MBR that was enough and the CD 1 made it right.