[villagetinker]

Some points of clarification. ALL OUTSIDE outlets MUST be protected by GFCI, as far as I know, there is no allowance for using twist lock type outlets. This also includes outlets in the garage, and those near water (bathrooms and kitchen, etc.). INSIDE the house, as I understand it, yes a dedicated circuit to the refrigerator, can be allowed as long as it is a certain distance from water (this needs to be verified with the building department).
OP, as you are aware, GFCI operate when the difference in the current between the HOT wire and the Neutral wire are more than 4.5 ma. This maybe due to the use of surge suppressing capacitors (or possibly leakage to ground of the motor starting capacitor) that connect to ground. The GFCI cannot tell the difference of a leakage due to the surge capacitor (or motor starting cap) or a person being electrocuted due to a broken wire. While I have a lot of electrical test equipment, I do not have a specific leakage detector.