These is an iPhone bug. The KCA-BT200 is an Parrot product so is the same unit like Parrot 3000. I have it installed with an Kenwood DNX7200 navigation and so on. The only one who can solve the issue is APPLE. But it seams that they made it on purpose, so everyone must buy the Bluetootth for iPhone from them (some thing similar to iTunes policy). They think they are crafty, but on long terms, these policy it will be dangerous for the iPhone sales.
My suggestions (what I am doing), is to take an old phone with Bluetooth, take another sim card with a diferent number (Twin card service or an Team servis, depends from the mobile provider), forward the calls to these sim card (optio only when my phone is swiched off). Pair the old phone with your Bluetooth in the car and every time you enter in the car switch off your iPhone and turn on your old phone. Another subbestion is to block the caller ID on your old phone so noone will get rhe other number from you and noone will call you on it after you exit the car.
These is the only way until APPLE will fix these issue, (uncript the iPhone's Bluetooth).