I have resolved the problem. The last kernel update appended "acpi=off" in my grub menu.lst. This disabled acpi and proper poweroff. Deleting this kernel parameter fixed things.
If there is a bug to address, it is in the scripts that update menu.lst when a new kernel is installed. My original menu.lst: menu.lst~ kernel /boot/vmlinuz-2.6.17-10-generic root=/dev/hda1 ro quiet nosplash Post update menu.lst: menu.lst kernel /boot/vmlinuz-2.6.17-11-generic root=/dev/hda1 ro quiet splash acpi=off -- latest kernel upgrade broke acpi and power off on MSI Neo4 https://launchpad.net/bugs/87251 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
