Shutdown button restarts Toshiba i3 laptop on Linux Mint 14

[Brahim]

I have installed Linux Mint 14 Cinnamon 64bit on a Toshiba i3 laptop and I have noticed something very unusual. When the charger in plugged in and I click on shutdown button, the laptop restarts instead of going off. But when I unplug the charger, i can shut it down normally. BTW the same thing happened when I installed Linux Mint 13 Mate. But on Windows I can shut down my pc even when the charger is plugged in.