I agree.  In the beginning, I had a few that would bypass me and send requests straight to my boss, or walk in and pass me and walk right into his office.  Even had one who would just walk in and interrupt when my boss and I were meeting.  It did not last long.  My boss talked to them or deferred them to me.  On occassion he will still defer to me for his scheduling.  However, most have received the message and now just come straight to me.