I have the NAV upgrade, using an iPhone with 2.2.1 software, and I still have the problem, but only occasionally. That occasion is usually when i get an important call while listening to the radio at a loud volume. How frustrating!!
Also, I cannot recreate the problem while sitting in my driveway and utilizing two phones. It will mute everytime. So I tried programming a destination and sitting in my driveway, thinking I will be taxing the computing system more. It still would mute every time.
Giving up, I head out the next morning, and it fails to mute the first call!! Using steering wheel button vs. touch screen doesn't seem to matter to me.
I will try to "hold" the green button next time and see if that has any affect.
Anyone else have a suggestion?
This drives me crazy.