Make XFCE power manager handle power button
XFCE power manager doesn`t handle power button actions by default, and the computers turns off without asking, even if it is defined to ask in the GUI of XFCE power manager. If you need to change it edit file /etc/acpi/acpi_handler.sh and replace the line below
power) /sbin/init 0
with this one:
In fact you could just delete or rename the file but this solution is more elegant.