I was running RHEL 6 and had no issues like this. After installing 12.04LTS when I try to shutdown and the computer reboots 2sec after the shutdown. Searching around it looks like I have plenty of company with this issue. I have tried,
- sudo apt-get install laptop-mode-tools.
- sudo vi /etc/default/grub, GRUB_CMDLINE_LINUX_DEFAULT="acpi=noirq quiet splash", sudo update-grub
- sudo shutdown -h now
- sudo shutdown -P now
- sudo init 0
- sudo poweroff
- Many BIOS changes, BTW, WOL is off.
- GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=force"
- GRUB_CMDLINE_LINUX_DEFAULT="" (This is where I am at now)
Nothing has worked yet but I have managed to screw up the shutdown so that it hangs on 4 dots within the splash but that is as close to a shutdown as I can get. If the machine shuts off it always comes back on after about 2sec. Now I could go back to RH but the 12.04LTS I have at home has spoiled me. I could also hunt down the relay that is triggering the auto start on the motherboard and lift a leg as I don't really care about restarts. I have the splash off now and I don't see any errors. It isn't a huge problem, I just have to hold the power button after shutting down but it is bugging the crap out of me!
Anyone think of something I missed?