Since upgrading to 10.8 the time displayed in the menu bar is always incorrect. Sometimes by minutes, or hours, other times it just displayes the same time (eg 3:13) for several days without changing. Opening System Preferences to try to adjust the time or for any reason results in a spinning beachball that last for 30-60 min, System Preferences never being able to be accessed at all. Have tried logging out/back in, restarts, etc.. but nothing helps. Ideas?