replacing GNOME Power Manager in XFCE4 on a laptop

I am running XFCE4 on my Eee PC, and since it was recommended to not use the GNOME Power Manager, I decided I'd implement the hack that allows you to use the XFCE battery manager and still have the power button bring-up the shutdown dialog... that hack is documented on the eeeXubuntu page... but there's a step missing: you have to tell X that your user is authorized to run programs like that on your display (this might seem like a bit bizzare to a Linux novice, but to those of us who grew-up running X11R6 from back in the day, it isn't too odd.) To do this, you have to add an entry to your /etc/X11/xserver/SecurityPolicy file:

property SCREEN_RESOURCES cjsteele ar aw

Once you've made the change, you just have to restart your X server -- I know you can do this without rebooting, but logging-out and logging-in didn't accomplish it, so I took the lazy path and rebooted. Now, it should Just Work.