systemsettings crashed with RuntimeError in _connect(): failed to connect to server

[Alvin]

Binary package hint: kdebase-workspace

This message appears every time I login after rebooting the system. I don't know yet where it comes from.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: systemsettings 4:4.6.2a-0ubuntu5
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Tue Apr 19 17:23:41 2011
ExecutablePath: /usr/bin/systemsettings
ProcCmdline: /usr/bin/systemsettings -caption System\ Settings -icon preferences-system
ProcEnviron:
 LANG=C
 SHELL=/bin/bash
SourcePackage: kdebase-workspace
Title: systemsettings crashed with RuntimeError in _connect(): failed to connect to server
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin backup cdrom dialout fuse libvirtd lpadmin plugdev sambashare users
XsessionErrors: (knotify4:2302): GStreamer-CRITICAL **: gst_debug_add_log_function: assertion `func != NULL' failed

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mechanical snail (replicator-snail)]

This happened when I opened KDE systemsettings's Printer Configuration after running `sudo service cups stop`. It seems it doesn't handle the case that the CUPS server isn't running.