Unable to update Fedora 12 System

[Lorne Preston Bailey]

Error Type: <class 'yum.Errors.RepoError'>
Error Value: Error getting repository data for installed, repository not
found
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 3125, in
<module>
    main()
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 3122, in
main
    backend.dispatcher(sys.argv[1:])
  File : /usr/lib/python2.6/site-packages/packagekit/backend.py, line
699, in dispatcher
    self.dispatch_command(args[0], args[1:])
  File : /usr/lib/python2.6/site-packages/packagekit/backend.py, line
657, in dispatch_command
    self.update_packages(only_trusted, package_ids)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 1948, in
update_packages
    signed = self._is_package_repo_signed(pkg)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 1437, in
_is_package_repo_signed
    repo = self.yumbase.repos.getRepo(pkg.repoid)
  File : /usr/lib/python2.6/site-packages/yum/repos.py, line 121, in
getRepo
    'Error getting repository data for $s, repository not found' $
(repoid)

Any suggestions?

Lorne Bailey