GUI.py crashed with AssertionError in chownself()

[ory1977]

Binary package hint: bleachbit

don't start

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: bleachbit 0.8.7-1
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
NonfreeKernelModules: nvidia
Architecture: i386
Date: Tue Mar 29 11:39:03 2011
ExecutablePath: /usr/share/bleachbit/bleachbit/GUI.py
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110328.1)
InterpreterPath: /usr/bin/python2.7
ProcCmdline: python /usr/bin/bleachbit
ProcEnviron:
 PATH=(custom, no user)
 LANG=it_IT.UTF-8
 LANGUAGE=it_IT:en
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/bleachbit']
SourcePackage: bleachbit
Title: GUI.py crashed with AssertionError in chownself()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: