cannot shut down when booted with upstart

[Glen Ditchfield]

When I boot my computer using upstart, I cannot shut down from the display manager's login dialog.

Steps:
1) Turn computer power on.
2) When the grub menu appears, select "advanced options for Ubuntu".
3) Choose option "Ubuntu, with linux 3.19.0-12-generic (upstart)".
    The boot process proceeds and the display manager's user ID/password dialog appears.
4) Click the "0/1" (shutdown) button.
    The shutdown window appears, displaying "Shutting down in 30 seconds".
5) Click the "shut down" button". The button changes color, but nothing else happens.
   The shutdown countdown continues.
    When the 30 second wait expires, the count continues into negative numbers:
    "In -2 seconds" ... "In -3 seconds" ... "In -4 seconds".
6) Clicking the "cancel" button" returns to the login dialog, and I can enter an ID and password to log in.

If I select systemd in the advanced options, or let the computer boot with the default options, the display manager can stut down the computer in the expected manner.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: sddm 0.11.0-0ubuntu9
ProcVersionSignature: Ubuntu 3.19.0-12.12-generic 3.19.3
Uname: Linux 3.19.0-12-generic x86_64
ApportVersion: 2.17-0ubuntu1
Architecture: amd64
CurrentDesktop: KDE
Date: Fri Apr 10 18:55:25 2015
InstallationDate: Installed on 2015-03-22 (19 days ago)
InstallationMedia: Kubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150224.1)
ProcEnviron:
 LANGUAGE=en_CA:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: sddm
UpgradeStatus: No upgrade log present (probably fresh install)