Comment 41 for bug 119308

I faced the same problem with my old IBM Thinkpad 380Z after installing Ubuntu 7.10 onto it -- the laptop did not shutdown. However, with Ubuntu 6.06.10 it used to. I added acpi=off and apm=on to the kernel booting line in /boot/grub/menu.lst, and also apm power_off=1 to /etc/modules. And I confirm Ubuntu starts up without "acpi=force is required" message and the laptop shutdowns properly.