Why don't you use also these lines to boot ubuntu manually before 'linux /boot/vmlinuz-2.6.31-14-generic root=/dev/sda1 loop=/ubuntu/disks/root.disk ro quiet splash' ??
insmod ntfs
set root=(hd0,2)
search --no-floppy --fs-uuid --set 18f86825f868037c
loopback loop0 /ubuntu/disks/root.disk
set root=(loop0)
Why don't you use also these lines to boot ubuntu manually before 'linux /boot/vmlinuz- 2.6.31- 14-generic root=/dev/sda1 loop=/ubuntu/ disks/root. disk ro quiet splash' ??
insmod ntfs disks/root. disk
set root=(hd0,2)
search --no-floppy --fs-uuid --set 18f86825f868037c
loopback loop0 /ubuntu/
set root=(loop0)