software-center crashed with DBusException in call_blocking(): org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

[Doug McMahon]

Software-center will only open promptly & work correctly once. Upon closing this crash is produced.
Upon reopening Sc it takes quite a long time - this is shown in terminal

$ software-center
2011-11-23 14:34:39,159 - softwarecenter.ui.gtk3.em - INFO - EM's: 17 13 20
2011-11-23 14:34:40,099 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2011-11-23 14:34:40,333 - softwarecenter.ui.gtk3.utils - INFO - Softwarecenter style provider for ambiance Gtk theme: /usr/share/software-center/ui/gtk3/css/softwarecenter.css
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 586, in msg_reply_handler
    reply_handler(*message.get_args_list(**get_args_opts))
  File "/usr/share/software-center/softwarecenter/backend/installbackend_impl/aptd.py", line 148, in _register_active_transactions_watch
    current, queued = apt_daemon.GetActiveTransactions()
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 143, in __call__
    **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 586, in msg_reply_handler
    reply_handler(*message.get_args_list(**get_args_opts))
  File "/usr/share/software-center/softwarecenter/backend/installbackend_impl/aptd.py", line 148, in _register_active_transactions_watch
    current, queued = apt_daemon.GetActiveTransactions()
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 143, in __call__
    **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
2011-11-23 14:35:32,119 - softwarecenter.ui.gtk3.app - INFO - software-center-agent finished with status 0

When it does open no packages can be installed or removed

The only way to restore is to delete ~/.config/software-center & do a full restart, Sc then works just once as before, ect.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: software-center 5.1.2.1
ProcVersionSignature: Ubuntu 3.1.0-2.3-generic 3.1.0
Uname: Linux 3.1.0-2-generic i686
ApportVersion: 1.26-0ubuntu1
Architecture: i386
CrashCounter: 1
Date: Wed Nov 23 14:35:06 2011
ExecutablePath: /usr/share/software-center/software-center
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20111122)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/software-center
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANG=en_US.UTF-8
PythonArgs: ['/usr/bin/software-center']
SourcePackage: software-center
Title: software-center crashed with DBusException in call_blocking(): org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #849553, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.