[SWLUG] Grub won't boot from second hard disc

[Edward Evans]

Can a Grub expert (or anyone else) help me with this?

I've been given a PC whose BIOS will boot from the 2nd hard disc (hdb).
So I installed Linux on hdb and put grub in the MBR of hdb.  The BIOS
finds grub stage 1 OK, and grub finds its boot menu from hdb2 and
displays it, but trying to run an option from the menu gives:

Error 17:  Cannot mount selected partition
for Linux and
Error 13:  Invalid or unsupported executable format
for the other OS

I've tried grub's "setup --force-lba" but that makes no difference.

BUT, and this is what puzzles me, if I put grub on the MBR of a floppy
and boot from that, up comes the menu and Linux and Windows boot fine
so the grub installation in /boot of hdb2 must be OK.

Is there some other option I should be using when I install grub, or
is it more likely to be a BIOS problem?  Or is the problem something
else that I haven't thought of?

Edward