If one's boss is acting differently, experts agree that it may be because he or she is a human being. Bosses, like all humans, are prone to stress and bad days, and may behave differently during these times. Out-of-character behavior could be caused by personal troubles or workplace stress. Employees may inquire as to why the boss is behaving differently, but only if the act does not undercut his or her superiority over them.
See "The Workplace: Is something wrong with the boss?", Matt Villano, International Herald Tribune, September 27, 2005