"Actually, Ground Fault is correct terminology. It means that there is a fault to TO ground, ie a fault between one of the current carrying wires and ground, allowing some current to flow directly to ground rather than through the neutral."
GCFI's are S-E-N-S-I-T-I-V-E
If more than a PREDETERMINED amount of current chooses to go to earth rather than negative it will fault the device. It absolutely does not have to be even close to 1/100th the amount of current going to neutral. This is a THRESHOLD grade problem and if you allow it to it will drive you nuts - for no reason IMHO.
A different BRAND of GCFI can cure this problem or "tuning" the feeder circuit like you are doing.
