backend_helper.py crashed with RuntimeError in add_signal_receiver(): To make asynchronous calls, receive signals or export objects, D-Bus connections must be attached to a main loop by passing mainloop=... to the constructor or calling dbus.set_default_main_loop(...)

This crash happens predictably on two very different laptops I tried -- when running the 1/28 daily live image from a USB pen drive, then choosing to try with persistent storage, then accepting the suggestion to install additional software.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: update-notifier-common 0.118.1ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-11.19-generic-pae 3.2.1
Uname: Linux 3.2.0-11-generic-pae i686
ApportVersion: 1.91-0ubuntu1
Architecture: i386
CasperVersion: 1.301
CrashCounter: 1
Date: Sat Jan 28 17:52:49 2012
ExecutablePath: /usr/lib/update-notifier/backend_helper.py
InterpreterPath: /usr/bin/python2.7
LiveMediaBuild: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20120128)
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/lib/update-notifier/backend_helper.py add_cdrom /cdrom
ProcEnviron:
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/lib/update-notifier/backend_helper.py', 'add_cdrom', '/cdrom']
SourcePackage: update-notifier
Title: backend_helper.py crashed with RuntimeError in add_signal_receiver(): To make asynchronous calls, receive signals or export objects, D-Bus connections must be attached to a main loop by passing mainloop=... to the constructor or calling dbus.set_default_main_loop(...)
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo