> It very well could be the shutdown dialog
I doubt it. He seems to be describing a message occuring after X has already been killed- like the shutdown message in text mode. Why this happens is beyond me- Plymouth should kick in for the shutdown procedure (at least if he's using Trisquel or Triskel). For me, the DE terminates, the screen goes black for a second, then the Plymouth wallpaper appears for a few seconds, and then the computer switches off. Strange.
