i'm posting this to the list in case it's of some use to somebody.
trying to get automounting of usb drives working on xfce, as discussed on a recent thread, i recompiled xfce4-session with policykit (polkit) and consolekit. eventually this got me automounting working, but in the process i lost the ability to shutdown or reboot the system from the exit dialog in xfce. it seemed obvious that it was a permissions issue involving polkit. searching the web i found instructions [*] that worked for me: create the file /etc/polkit-1/localauthority/50-local.d/power.pkla (the name isn't relevant as long as it's under that directory and has the pkla extension) with this code: [Local restart] Identity=unix-group:wheel Action=org.freedesktop.consolekit.system.restart ResultAny=yes ResultInactive=no ResultActive=yes [Local shutdown] Identity=unix-group:wheel Action=org.freedesktop.consolekit.system.stop ResultAny=yes ResultInactive=no ResultActive=yes [Local restart - multiple] Identity=unix-group:wheel Action=org.freedesktop.consolekit.system.restart-multiple-users ResultAny=yes ResultInactive=no ResultActive=yes [Local shutdown - multiple] Identity=unix-group:wheel Action=org.freedesktop.consolekit.system.stop-multiple-users ResultAny=yes ResultInactive=no ResultActive=yes you can change the Identity=unix-group:wheel line with a different group or a unix-user. since i'm the only user here, this isn't relevant for me. i hope this might be of some interest. [*] here: https://wiki.archlinux.org/index.php/Xfce