I take it that you have checked the temperature on the freezer with a thermometer.It should be at minus 18c or lower. The warmth between the lower and upper divider is either an electric trim heater or more likely part of the tubing which carries the warm refrigerant before going out to the condenser at the back of the fridge to stop the freezer door surround icing up or sweating. Sometimes its just the thermostat if mechanical which has a secondary set point at which to give an alarm. Has the freezer got on external fan to assist the condenser,the black thing at the back, looks like a radiator? maybe wants brushing out? Best I can do!
Keith, August 2010