Try setting the Turn Monitor off after setting to 1 minute and then wait to see if it does shut down after a minute.
That is strange because when I press the power button, the screen goes black and I see the blinking command prompt cursor for about 2 seconds and then my screen shuts down.
What is the version and date of your bios? The Power page of my bios has something called power savings but it only has options for Enabled or Disabled. This may work better for you if you have a different bios or maybe it has something to do with running ME. I don't know.
Has anyone had any luck with this?