None of you guys asking about sound on HDMI have said what device you are connecting to. I get perfect audio on my Samsung HDTV from the generic MHL adapter on the Flyer via HDMI cable. Not every TV or device is capable of receiving audio over HDMI. That's why they added the extra 3.5 analog audio jack as an option.
The Blackmagic Intensity Pro should work fine with either HDMI audio or analog audio. have you checked it with a known good HDMI source such as a DVD player or Cable box?
Days of free media are almost over as the biggies look for more revenue streaming from your wallet... ...Don't believe me? Take a look at all the flagship models now being sold WITHOUT microSD card slots.