problem with oil pressure light/buzzer

[demoG40]

hello.

I have a problem with my G40, I put a video so you can see light bulb as oil pressure, but the buzzer does not sound, and does it under 2000 rpm, and the car manual says that below 2000 rpm can not light or sound.

the oil level is correct.

when that happens, soon after you stop.

the buzzer function properly, which in turns fast if it sounds and lights.

forgive for my English, am Spanish and use the google translator.

a greeting.

and video

http://www.youtube.com/watch?v=8_tAzgW9HHE