Toshiba C850 laptop is automaticaly restart after shutdown

[TomBoj]

Toshiba C850 laptop is automaticaly restart after shutdown. OS is Ubuntu 12.04LTS clean install.

SATELLITE-C850:~$ lsb_release -rd
Description: Ubuntu 12.04.1 LTS
Release: 12.04

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: acpi (not installed)
ProcVersionSignature: Ubuntu 3.2.0-32.51-generic-pae 3.2.30
Uname: Linux 3.2.0-32-generic-pae i686
ApportVersion: 2.0.1-0ubuntu14
Architecture: i386
Date: Mon Oct 22 21:13:59 2012
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release i386 (20120817.3)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=hu_HU.UTF-8
 SHELL=/bin/bash
SourcePackage: acpi
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Philip Wyett (philip-wyett-deactivatedaccount)]

I also get this issue on my Toshiba L850-112 running Kubuntu 12.04 LTS 64-bit.

[Philip Wyett (philip-wyett-deactivatedaccount)]

To give more detail...

This issue only arises when doing a shutdown with the mains attached and live. Unplugging the mains and performing a shutdown works as expected.

[JACK FRECHETTE (jmfrechette)]

how do you repair a bug of automatic restarts on shutdown on unbuntu 12.04?