Macbook Pro Built-in Mic?

On my old 12" powerbook, I simply ran the built-in mic into Reaktor 4 to generate some nice lo-fi effects. Now, I'm setting up Reaktor 5 on a 13" Macbook Pro but I can't find a way to hook up the built-in mic. I've configured both sys preferences and audio midi setup for the mic input and the vu-meters show that it is, indeed receiving sound. Then I go to Reaktor and double-click on the Audio In box in the Ensemble-Structure window, which brings up the green audio setup window. There, in Routing, I try to configure inputs 1 and 2 for the internal microphone, but they always read -not connected-

What am I doing wrong?

Also, a much smaller problem: I've included Skrewell in my ensemble and used "properties" to make the lisajous screen smaller, then clicked on the little wrench and dragged the other controls up next to it. For some reason, the green background doesn't shrink to fit. It remains the same size, even though there are no longer any visible controls in most of the area. So how do I get that background to shrink? Or is it some kind of skin that I can eliminate? If so, where do I go to eliminate it?

Thanks very much for your advice!