GRUB and why root!=root

It one of the this 'keep in mind notes'. I tried to install the Fedora 9 along the Ubuntu 8.04. The Fedora went onto the sdb3 partition or (hd1,2) in the GRUB notation. I added following lines to the Ubuntu /boot/grub/menu.lst file. (I didn't install GRUB from Fedora).

title        Fedora 9
root        (hd1,2)
kernel        /boot/vmlinuz-2.6.25-14.fc9.i686 root=/dev/sdb3 ro
initrd        /boot/initrd-2.6.25-14.fc9.i686.img

But it wanted to work. All the time, I got Error 2 : Bad file or directory type. After trying many things I figured out that problem is lack of the GRUB files at the Fedora partition, so I updated grub config file.

title        Fedora 9
root        (hd0,0)
kernel        (hd1,2)/boot/vmlinuz-2.6.25-14.fc9.i686 root=/dev/sdb3 ro
initrd        (hd1,2)/boot/initrd-2.6.25-14.fc9.i686.img

Finally, the Fedora started to boot.