STOP THE ACPI=FORCE BOOT MESSAGE

Edit your /boot/grub/menu.lst (or /boot/grub/grub.cfg for Grub2)

Find this entry (your kernel and hard disk/partition specifications might be different and you may not have a UUID entry) and add the part in blue.

title Ubuntu, kernel 2.6.20-15-generic
root (hd0,5)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=3015a7a1-6e5d-42d6-934d-193459bed89b acpi=force
initrd /boot/initrd.img-2.6.20-15-generic
quiet
savedefault