Over here, ranges are exempt from RCD protection, mainly because of this Leakage current problem.
It's the same for Refrigerators,Hot Water Cylinders and Air Conditioning equipment.
With respect to ranges though, I'm not sure if it was mentioned above, but due to the heating and cooling cycles within the range body itself, during operation, there will tend to be a small, but appreciable build-up of moisture, that can slightly alter the Insulation Resistance values of the appliance, this is normal and any range that has a Minature Circuit Breaker protecting it(at the switchboard), should be fine.
[This message has been edited by Trumpy (edited 07-17-2003).]