>>120
/boot/grub/menu.lst の中身です

title Debian GNU/Linux, kernel 2.6.18-6-486
root (hd0,0)
kernel /boot/vmlinuz-2.6.18-6-486 root=/dev/sda1 ro
initrd /boot/initrd.img-2.6.18-6-486
savedefault

title Debian GNU/Linux, kernel 2.6.18-6-486 (single-user mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.18-6-486 root=/dev/sda1 ro single
initrd /boot/initrd.img-2.6.18-6-486
savedefault

＊ ちなみに root = /dev/*** の部分は書き換えております.