Doing a digital video upgrade for a historic movie theater -- brand new 3D-capable projectors that cost more than my house. Everything's checked out great, the

Doing a digital video upgrade for a historic movie theater -- brand new 3D-capable projectors that cost more than my house. Everything's checked out great, the projector has run perfectly for test screenings. Fast forward to opening night, half an hour before showtime, somebody opens the door to the control room and the projector suddenly shuts off. No warnings, no chimes, just crash shutdown. They start it back up, and a few minutes later the same thing happens again when the door is opened. They managed to keep the door closed through the opening night showing, and got the manufacturer on the phone ASAP. Manufacturer goes through the super-secret diagnostic log files. Turns out that the only difference between testing and opening night was that the front doors of the theater were open, and it was a windy night. The projector has a "wind vane" style airflow sensor in its exhaust vent to check and double-check that the fans are running correctly. The sudden changes in airflow when the control room door was open was enough for the airflow sensor to drop and trigger a panic shutdown. Since the projector also had fan sensors and temperature sensors, the manufacturer okayed us to bypass the airflow sensor.