I have a Mac Mini connected to my VSX-1020 via the HDMI Channel 1 with cable supplied with the mini, but no sound comes out of the center channel even though the input display indicator shows that the center channel is being input. I have a VUDU player, Time Warner Cable and a PS3 play connected, they all work fine Any idea what I could be missing? Note: I'm a PC guy, this is my first Apple device.