That may not be all that abnormal. I've had several cars that even with it set to recirculation some outside air is forced in while driving. But still, take it to the dealership and see if they can check the seals in the ventilation system.
Air leaks? Its called ventilation, its your fresh air setting, even in the off possition it will bring fresh air in...as a smoker, Id turn my vent off...but if your a non smoker and this just annoys you, turn the setting to recycle, that should stop it...but really its quite normal.