System preferences not working after OS 10.8 upgrade

Just upgraded to 10.8 from 10.7. All seems fine BUT most of the system preference panes don't work. The message is "To use the "whatever" preferences pane, System Preferences must quit and reopen." If I select OK it indeed quits and reopens but the same alert appears.

System Prefs verson is 12.0. Is that the correct one for OS 10.8? What is going on here? Do I have to try a reinstall? (Several restarts have not helped.)

Thanks for your thoughts.