The office has an iPad that is often used for Skype and GoToMeeting. it's an older iPad 3, with a 30-pin port. I've been unable to push audio and video to our office projector system via a 30-pin/HDMI adapter. Pushing audio and video to the projector system using HDMI with any other device (Windows laptop, Mac laptop, Elmo...) has been seamless.
It's worth noting that I've tried to push audio and video from the iPad/30 pin/HDMI adapter to a large screen TV in the office as well. I can push video, but have had no luck with audio.