Overvoltage indication with SMPS

Whenever I turn off SMPS .The Overvoltage LED on Beagleboard-xm
glows.but actually the o/p voltage of SMPS steadely decreases as
measured on the multimeter.So is there any problem with such usage

The circuit detects over voltage and under voltage. Turn off your power supply and at some point, it will the circuit will detect it as an undervoltage condition.