Energy Saving - Button events handling


I have Dell Inspiron One (all in one pc) which I have upgraded from 12.2 to 12.3 (64bit) after the upgrade I can’t turn the display off any more by pressing the power button. No matter what I set in “Configure Desktop → Power Management → When power button pressed”. I have tried to change it to any of the values but when I press power button it will always shutdown the computer. This worked previously in 12.2 before the upgrade.

Any tips how to solve this annoying issue?

This works with 12.3 Live DVD so it has something to do with the upgrade. Where is this configuration saved?