I read your post as I had a strange problem with mine, when I hit a bump on the left side of the car I got warm air through the drivers side vents - turned the control on then back to off position and all was well.
As today is the first cooler day we have had since December I didn't have the airco running. These problems must turn up at every change in season.
Anyway, checked out the archives typed in "heater control" and there are many responses to our problems.