We had exactly the same problem with exactly the same model of fridge. I realised that the door had sagged slightly and wasn't operating the switch located above the top edge of the door which turns off the light inside the fridge, the light was staying on when the door was closed and the heat from the bulb was raising the temperature inside the fridge. I didn't know how to adjust the door so I just folded some paper until it was thick enough to operate the light switch when taped to the top edge of the door. This has worked successfully for a few years now.
Al Haleman
August 2007