Acredito que basta tirar o quiet da linha kernel no arquivo /boot/grub/menu.lst.
title Ubuntu 7.04, kernel 2.6.20-16-generic
root (hd0,5)
kernel /boot/vmlinuz-2.6.20-16-generic root=/dev/hda6 ro quiet splash locale=pt_BR
initrd /boot/initrd.img-2.6.20-16-generic
boot