I just tried running 'dpkg --configure -a' from a text VT whilst gdm was still running, and it was fine. So it seems to be something about the postinst running inside a gnome-terminal that breaks things.
I just tried running 'dpkg --configure -a' from a text VT whilst gdm was still running, and it was fine. So it seems to be something about the postinst running inside a gnome-terminal that breaks things.