Hi guys, sorry i didn't read the entire thread, but i just got this message from an Audioengine support tech about the D1:
"Thanks for emailing and for your interest in our products. We have tested the D1 on the iPad 2 using the Apple Camera Connection Kit and a D-Link Dhub-H7. It worked great. We also found that the D1 was not receiving enough power when we did not use the powered USB hub. I hope this helps and let us know if you have any other questions.