Ubuntu 11.10 will not shut down or restart

Yes, it's a fairly unusual problem. One reason might be because of the way the shutdown is being initiated by the shutdown signal. If it's related to this then pressing the power button once (don't hold it) should do the same thing. You should get a window pop up asking if you want to shut the computer down just the same as if you had clicked shutdown on the menu. You might try this and see if does nothing (or if it works).

You could also try changing the default grub settings. Do the following in a terminal:

#edit the /etc/default/grub file with nano (or other editor)
sudo nano /etc/default/grub

#change the line that reads
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
#to:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux"
#then save the file and exit.

#you will then need to run update-grub:
sudo update-grub

#and reboot the computer to see if it's had any affect:
sudo reboot

Chris

Thanks for this -I'll try it, when I have time. And nope, when I press the power button and the prompt window comes up and I press either reboot or shutddown, STILL nothing happens. Why doesn't Ubuntu fix what appears to be a bug?

The bug isn't in Linux, it's a problem with some older BIOSs and the way they were written. Try the acpi_osi fix and if that doesn't work investigate what other options there are for this configuration item and try them.

Chris

P.S. I don't have an old BIOS, I have a new laptop: Dell Inspiron.

Then it's an old problem that the BIOS manufacturer can't be bothered to fix. Someone else had the same problem and they just fixed it with the same solution:

https://answers.launchpad.net/ubuntu/+source/acpi/+question/186804

You didn't say whether or not the fix had worked in your case.

Chris