Passenger side bows HOT

Hello- 2004 suburban with auto climate control. The passenger side tends to blow hot air whe it set to a cool temp. If I shut the unit off for a few minutes while driving it usually resets itself to normal operation.
I will pull the fuse later to reset the system, as I found that suggestion on the the Tahoe board.
Could it be the actuator is gong bad? It was into the dealer about a yr ago under warranty and they could not duplicate the problem.
I dont notice it too much, but when the wife sits in the passenger seat, she gets a face full of hot air.

Any Help will be appreciated!
Thanks
Paul