need grub help with new PC

[Ken N9VV]

Hi, I have a new Dell PC. It has a single 160GB SATA-II drive. I 
used Acronis and copied all my old partitions to the new drive 
(painful process).  The windows partition comes up just fine. Now I 
am trying to get grub-install to re-write the MBR so I can boot to 
Ubuntu with my spiffy new Video card.

But I can't get grub-install to work at all. It complains that the 
target device is NOT listed in the BIOS. I tried the following with 
NO luck:

o   boot live Ubuntu (or Knoppix, or Mepis or Helix).
o   become root for all commands
o   mount /dev/sda5 /mnt (always successful)
o   edit the /mnt/boot/grub/menu.lst and make sure that the 
/dev/sda5 are all set. Edit the /etc/fstab so it is happy.

do a fdisk -l command to see all the available partitions. 
Everything looks normal and all partitions are /dev/sdX as one would 
expect.

then try any of the following with NO joy:
------------------------------------------
grub-install --root-directory=/mnt /dev/sda
grub-install --root-directory=/mnt /dev/hda
grub-install --root-directory=/mnt /dev/sd0

all complain that the target device is not in the BIOS. In the past 
I totally screwed up my NTFS partition (/dev/sda1) by allowing 
grub-install to dribble all over the windows partition. So I know 
that sda1 is NOT the answer <g>

Without the --root-directory-/mnt grub-install is UNhappy about the 
fact that I am running as root on another O/S from the CDROM.

any suggestions please?
thanks,
Ken