Handset keypad backlight may stay lit on cradle

bug

#1

It may occur that the keypad on one of my many DP730 handsets stay lit even if it has been on the cradle and untouched for many hours. This can affect any of the handsets, maybe twice a month. It occurs on the latest firmware version and also the previous ones. It persists after a factory reset of the base station and all handsets.