Standby and suspend buttons greyed out

[Sergio]

- systemd-inhibit isn't running
- xfce4-power-manager manages for sure the 'power' and the 'sleep' keys 
in Xfce for me just as in F17. I know that because of what I wrote 
before: when I hit the power key the logout dialogue pops-up and when I 
hit the sleep key the system suspends and locks the screen on resume 
(only xfce4-power-manager is set to do that).

So I said that it could be acpid inhibiting it because of you saying 
that xfce4-power-manager doesn't do that. But one other possibility is 
simply that the 'power', 'suspend', 'hibernate' and 'lidswitch' keys are 
not the usual 'power' and 'sleep' keys in the keyboard.
I'm on a desktop PC, not a laptop.

This is the default, untouched, /etc/systemd.logind.conf

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.
#
# See logind.conf(5) for details

[Login]
#NAutoVTs=6
#ReserveVT=6
#KillUserProcesses=no
#KillOnlyUsers=
#KillExcludeUsers=root
#Controllers=
#ResetControllers=cpu
#InhibitDelayMaxSec=5
#HandlePowerKey=poweroff
#HandleSuspendKey=suspend
#HandleHibernateKey=hibernate
#HandleLidSwitch=suspend
#PowerKeyIgnoreInhibited=no
#SuspendKeyIgnoreInhibited=no
#HibernateKeyIgnoreInhibited=no
#LidSwitchIgnoreInhibited=yes


What I said is that 'LidSwitchIgnoreInhibited=yes' just does what you 
and Raphael were talking about: if the user don't change that value then 
xfce4-power-manager's settings are ignored (in case it inhibits 
systemd-logind.service).