Can't get audio to play out of my HDTV speakers when I connect my 2011 MBA to the TV. I was under the impression that Thunderbolt/MDP did both audio and video ever since the MBP featured it in 2010. I'm using MDP/HDMI cable that I got from Monoprice last year before they were ruled illegal. Right now when connected video is fine but audio is emitting from MBA speakers instead. Trying to avoid using a second wire strictly for audio.