Hmm, it makes me wonder what different methods radio manufacturers use for Bluetooth headset functionality. Like on my aftermarket Kenwood unit, it downloads my phonebook to the car every time it turns on (which is normal, I'm assuming it doesn't store them permanently or checks for changes), and then the headset functionality works perfectly after that. I had zero problems with both my Eris and the Nexus (at least in the short time I've had it). I thought it would be a pretty simple and standardized thing to implement but maybe not.