My 2006 F150 STX has something strange going on with the AC control. If I switch from defrost to floor/defrost, AC automatically turns on. If I turn the AC off and switch the dial to off, the AC turns on again, then it won't let me turn it off. This has been a nuisance for me since I bought the truck, and now that I'm down to 6 weeks remaining on the factory warrenty, I'm wonderign if anyone else has had this problem or if my HVAC controls are jacked and I need take it in for replacement.