Pure Music Question

I have a question about how to use Pure Music with a wireless system. I currently have three systems, one using an Airport Express and two using Apple TV's connected to external DAC's. Music resides in a 1 TB hard drive connected via an Apple Airport wireless. Everything is controlled by iTunes running on an iMac using an iPod Touch with the Remote app.

I have downloaded the Pure Music demo and run into a hitch. It launches seamlessly but fails to play through any of the "speakers" I have selected in iTunes. When playing straight through iTunes without PM, no problem. It does play through my iMac speakers and I think sounds like a big improvement, but who listens through internal desktop speakers?

I have been able to highjack the PM stream and direct it to my systems using Airfoil, but short of using a desktop controller on my iPod Touch, nothing else works. PM seems like a great and reasonably priced upgrade, but to make it practical, I need to be able to use my Touch to control iTunes remotely while PM is running. I have spoken with PM's tech support, but no luck.

Any ideas?