GRUB not written to MBR - rewrite problem

[Claude Jones]

On installation, GRUB was supposed to be written to the MBR, but it didn't 
happen. FC5t2 is installed on an external USB drive, connected to my HP 
Pavilion Laptop. I've run several Linux distros this way, so I know it can 
work. I booted into rescue (I also tried "linux expert rescue"), but after I 
"chroot /mnt/sysimage" and type "grub-install /dev/hda" I get the following:

"/dev/mapper/VolGroup00-LogVol00 does not have any corresponding BIOS drive"

Can anyone suggest something? I get the same message if I try to write GRUB 
to /dev/sda by the way...
-- 
Claude Jones
Bluemont, VA, USA