a bug windows appear saying that there is a system error

[Mohammad Alkahtani]

Error Type: <type 'exceptions.TypeError'>
Error Value: coercing to Unicode: need string or buffer, exceptions.SystemError found
  File : /usr/share/PackageKit/helpers/apt/aptBackend.py, line 2216, in <module>
    main()
  File : /usr/share/PackageKit/helpers/apt/aptBackend.py, line 2213, in main
    run(args, options.single)
  File : /usr/share/PackageKit/helpers/apt/aptBackend.py, line 2175, in run
    backend.dispatcher(args)
  File : /usr/lib/python2.6/dist-packages/packagekit/backend.py, line 699, in dispatcher
    self.dispatch_command(args[0], args[1:])
  File : /usr/lib/python2.6/dist-packages/packagekit/backend.py, line 606, in dispatch_command
    self.refresh_cache(force)
  File : /usr/share/PackageKit/helpers/apt/aptBackend.py, line 202, in _locked_cache
    func(*args, **kwargs)
  File : /usr/share/PackageKit/helpers/apt/aptBackend.py, line 1498, in refresh_cache
    format_string(error.message))
  File : /usr/lib/python2.6/dist-packages/packagekit/backend.py, line 723, in format_string
    txt = unicode(text, encoding, errors='replace')

[Mitch Towner (kermiac)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 546607, so it 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.