I have a MBP and am using: Mini display port DVI adapter --> DVI to HDMI cable --> into my TV's HDMI port. I get no sound out of my TVs speakers. I thought I could sound via HDMI this way (that's what I was told). I have an optical audio out going from my TV to my stereo 5.1 receiver. Why can I hear no sound? Did I misunderstand something? Do I need to do something else to have sound? Thanks!