Apologize if this has ever been covered before, but while I watching the Steeler-Bengal game yesterday, I noticed numerous times where the volume would noticably go up or down; I believe sometimes there was an audible click associated with it. I have noticed this while viewing numerous programs, but it was especially annoying yesterday. These changes were not associated with the show going to commercial, either. For the purpose of this problem, my cable box is connected directly, via HDMI, to the Panny plasma set I have--no AVR was involved. Has anyone else experienced this during a show? TIA.