Curve and Kenwood KDC-BT742U

First of all, I like this a lot. Once set up, the handsfree is wonderful. Auto-attentuates audio, answers with one button press on the head unit, great reported quality at both ends. Can be paired up at either end and set up. Syncs address book automatically.

I have one minor disappointment, and if anybody here knows anything about this I figured this would be the best place to come for constructive input. The bluetooth functions flawlessly on the Kenwood head unit as a telephone handsfree, but doesn't seem to be able to use BT as an audio source. I start my Slacker radio, enable bluetooth, but the head won't play it. I know the head is connected because if I go into the menu and put it in a ready state for voice recognition, there's the Slacker radio output on my speakers. Does nyone know of another way to have the Kenwood KDC-BT742U use Bluetooth as an audio source instead of just a phone handsfree?