help, weird bug

[hagr182]

Guys I seriously need your help, my brother was messing around with my f10
laptop and now everytime i search for packages or try to install anything it
gives me this error, please we need your help:


Error Type: <type 'exceptions.TypeError'>
Error Value: 'NoneType' object is unsubscriptable
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 2202, in
<module>
    main()
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 2199, in main
    backend.dispatcher(sys.argv[1:])
  File : /usr/lib/python2.5/site-packages/packagekit/backend.py, line 610,
in dispatcher
    self.dispatch_command(args[0], args[1:])
  File : /usr/lib/python2.5/site-packages/packagekit/backend.py, line 561,
in dispatch_command
    self.search_group(options, searchterms)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 479, in
search_group
    pkgfilter.add_available(self._get_available_from_names(all_packages))
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 363, in
_get_available_from_names
    pkgs = self.yumbase.pkgSack.searchNames(names=name_list)
  File : /usr/lib/python2.5/site-packages/yum/__init__.py, line 592, in
<lambda>
    pkgSack = property(fget=lambda self: self._getSacks(),
  File : /usr/lib/python2.5/site-packages/yum/__init__.py, line 435, in
_getSacks
    self.repos.populateSack(which=repos)
  File : /usr/lib/python2.5/site-packages/yum/repos.py, line 223, in
populateSack
    self.doSetup()
  File : /usr/lib/python2.5/site-packages/yum/repos.py, line 71, in doSetup
    self.ayum.plugins.run('postreposetup')
  File : /usr/lib/python2.5/site-packages/yum/plugins.py, line 176, in run
    func(conduitcls(self, self.base, conf, **kwargs))
  File : /usr/lib/yum-plugins/rpm-warm-cache.py, line 31, in
postreposetup_hook
    if commands[0] in ('upgrade', 'install', 'remove'):