software-center crashed with AttributeError in show_diff(): 'NoneType' object has no attribute 'group'

just started it then the error

ProblemType: Crash
DistroRelease: Ubuntu 12.10
Package: software-center 5.3.5
ProcVersionSignature: Ubuntu 3.5.0-6.6-powerpc-smp 3.5.0
Uname: Linux 3.5.0-6-powerpc-smp ppc
ApportVersion: 2.4-0ubuntu6
Architecture: powerpc
Date: Sat Jul 28 06:03:55 2012
ExecutablePath: /usr/share/software-center/software-center
InstallationMedia: Ubuntu-Server 12.10 "Quantal Quetzal" - Alpha powerpc (20120606)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/software-center
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/software-center']
SourcePackage: software-center
Title: software-center crashed with AttributeError in show_diff(): 'NoneType' object has no attribute 'group'
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo