I've also noticed something else. Every other time I connect to my stereo, it doesn't ring through the stereo, just through the headset.

It says that it's connected to the stereo, I can see the number on the screen, but cannot hear anything. I have to switch the audio to the device, then switch back to the Bluetooth - and if that does not work, I have to turn Bluetooth off on the phone, then turn it back on then it'll play through the stereo and I can use the hands-free that way.

I've had issues with streaming Bluetooth audio from the N9 to my stereo, but I had issues with Android and WP7 - iffy at times.