ACPID .pet

Add this line .xinitric file

acpi=force

make sure it is at the top of the file

More info here: (Enables power button shutdown on machines having shutdown problems)
http://www.murga-linux.com/puppy/viewtopic.php?t=38173

Please don't let the title of the thread throw you the second .pet is the required one version 1.0.10 of Acpid.