Make sure that Bluetooth is set to always on.

You said it worked perfectly for a while and now it does not. That tells me that the wiring is correct. I would tend to think that something is wrong with the ULF module, you mentioned getting an early 1st gen from the dealer, OR something wrong with the phone. I would check the settings.

Also make sure that the sytem is somehow not putting you in privacy mode. You can press the pairing button when you get in and start the car in the middle of the call to transfer audio from the phone to the car.

Maybe something nutty is going on with that ULF module. It is the ULF that provides charging to the phone. Plus determines how the audio transfer should be handled. Visteon made a significant about of changes from the early 1st generation ULF module to the 6th Gen. such as completely redesigning the system with a new and better DSP, tweaking the audio quality to fine tune it for better audio performance, and modifying the phone profiles to support more Bluetooth phones and handle the calls more efficiently. They also optimized the radio circuit in order to stabailize the radio frequency generation of the Bluetooth signal.

Hope this helps
Martin