I've had my current my current x-10 system in operation for over two years. One of the MS18A motion sensors recently started setting off the alarm within seconds of arming in away mode. The activated sensor displays on the SC12A console. Removing the affected sensor zone from the console allows the system to be armed in away mode without event. I attempted re-installing the MS18A and the problem returned. I relocated the MS18A to a location where there was no heat source or possibility of motion to be detected and the problem persisted. I re-tried initial sensor setup and installation multiple times with no change. I observed the sensor from a 90 degree angle, out of the sensing range, and noticed the green LED flashes every 30 seconds even when there is no possible movement. Is the sensor faulty or is there a fix? The system works normally with this sensor removed from the system.