We have a Professor Motor 4 lane photo sensor lap counter system in both of our tracks (oval and a road course). We use their SRM (Slot Race Manager) DOS program to report lap times. You can see the system at their website: http://www.professormotor.com/lapcounters.shtml

On the oval course, one lane is not working correctly. Once you start the program, the red lane immediately posts a time (before a car has even moved on the track) and will not report anything else when the photo sensor beam is broken.

Anyone have any idea what could be the problem?

Thanks,

Don @ Cloverleaf Speedway

Sounds like either a mis-aligned emmiter/sensor or a "too dim" emmiter (underpowered or too far from sensor). Try holding a bright led flashlight about an inch or so over the sensor and trigger it with your fingers.