Sprint HTC Hero :: Car Stereo Hands-Free Bluetooth Errors

I have a Blaupunkt Melbourn car stereo with the Blaupunkt USB/Bluetooth Interface installed in my car and it used to work just fine with my Sprint Mogul and Touch Pro, but I can't seem to make it work with my Hero. When I pair the two, the radio only recognizes the Hero as an audio source and not as a phone. In other words, I assume I can stream music from the phone to the radio but I can't answer the phone with it. I should add that the connection icon shows up as audio headphones instead of a phone handset in the Bluetooth Devices screen.And this is just the opposite of what I need. I could care less whether I can stream music, but I need to be able to use the car radio as a hands-free device and as I wrote in the last paragraph, the radio worked perfectly in that capacity with my last two phones.So does anyone have any idea whether this is a phone problem or a stereo problem? Does anyone have any idea if there's a work-around? For that matter, does anyone have any helpful information at all?