Description of problem:
An internal system error appears when searching for a term with special characters such as German umlauts (ä, ö, ü, ...)

Version-Release number of selected component (if applicable):
gnome-packagekit-0.3.14-1.fc10.i386 (as well as later builds)

How reproducible:
always

Steps to Reproduce:
1. Enter a search term with at least one special character in the search fild
2. Press "Find"
  
Actual results:
Error Type: <type 'exceptions.TypeError'>
Error Value: 'in <string>' requires string as left operand
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 2316, in <module>
    main()
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 2313, in main
    backend.dispatcher(sys.argv[1:])
  File : /usr/lib/python2.5/site-packages/packagekit/backend.py, line 600, in dispatcher
    self.dispatch_command(args[0], args[1:])
  File : /usr/lib/python2.5/site-packages/packagekit/backend.py, line 567, in dispatch_command
    self.search_name(options, searchterms)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 332, in search_name
    self._do_search(searchlist, filters, key)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 293, in _do_search
    self._do_meta_package_search(fltlist, key)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 270, in _do_meta_package_search
    if key in grpid:


Expected results:
Just works (TM)