Shutdown button unresponsive

[royaleagle]

I am workinh on a mis nettop 110 with atom 230 and 2gb of ram.
There is no problem powering on the computer, the problem is on the shutdown, if I press the button immediatly after the computer finished booting no problem the computer turns off.
But if I use the computer normally and at a moment I press the shutdown button Well nothing happens... I need to go on the menu to shut it down
I must inform you that I chose the good option un power settings.
Oh and sometimes it doesnt shutdown but display the shutdown menu.

Thabks for the help