With the dual temperature control, the vents blow cold air on the passenger side no matter what temperature setting I used. The air on the driver side vents continued to respond to temperature adjustments. This is very cold for a passenger, even in Texas, in December and January. The dealer, "5 Star Ford" in Plano, TX told my wife when she picked the car up that we should make sure to turn off the Heat/AC every time we shut the vehicle down and that should cure the problem. Sometimes this works, sometimes it doesn't.

Update from Dec 10, 2012: Here we are one year later and we still have intermittent problems with the same issue. Now that the weather has turned cold again it is more noticable. Turning the Heat/AC off each time does not seem to work. The dealer still seems puzzled that we have problems with this. I have found that turning both the driver side and passenger side temperature controls as low as they will go and then slowly turning the passengers side temperature control up to a desired temperature seems to fix the problem. I can then increase the drivers side temp up to a comfortable level also. Hope this helps.