ubiquity crashed with DBusException in call_blocking(): org.freedesktop.DBus.Error.ServiceUnknown: The name :1.72 was not provided by any .service files

ubiquity crashed with DBusException in call_blocking(): org.freedesktop.DBus.Error.ServiceUnknown: The name :1.72 was not provided by any .service files

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: ubiquity 2.7.17
ProcVersionSignature: Ubuntu 3.0.0-9.14-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
Architecture: amd64
CasperVersion: 1.279
Date: Sun Aug 28 13:41:24 2011
ExecutablePath: /usr/lib/ubiquity/bin/ubiquity
InterpreterPath: /usr/bin/python2.7
LiveMediaBuild: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110828)
ProcCmdline: /usr/bin/python /usr/lib/ubiquity/bin/ubiquity gtk_ui
ProcEnviron: Error: [Errno 13] Permission denied: '/proc/5203/environ'
PythonArgs: ['/usr/lib/ubiquity/bin/ubiquity', 'gtk_ui']
SourcePackage: ubiquity
Title: ubiquity crashed with DBusException in call_blocking(): org.freedesktop.DBus.Error.ServiceUnknown: The name :1.72 was not provided by any .service files
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: