Accessing second hard disk

[bdc]

Have grub working wonderfully on first hard disk.
When I add an entry to menu.lst  to have grub find my second
hard disk it claims  to find an unkown file system where it should find 
an ext2
file system. I know it's there as I can boot it with a floppy or mount 
and access it from my first hard drive. Used command completion so the 
syntex must be correct.
root (hd1,0
kernel /vmlinuz root=/dev/hdb1

Ben Cobb