I have a church with a 50L(latest release) that has 12 each 24 key phones. When a phone receives or makes a call the red message light flashes like a message. Only way to extinghish the light is to unplug phone or power down 50L. It's not a message because the voicemail key doesn't flash. I am not the tech...just relaying message...... Any ideas? Could it be something to do with call logging?