I made extensive use of GFCI circuit breakers during the rewiring of my home. All receptacles on all circuits were properly wired with grounding wires. The ground wires were connected to the fixtures as prescribed by installation instructions. My problem is with two garage outdoor light fixtures. They are on a circuit that also feeds lights and garage door openers in the garage. These outdoor wall lights are 35 watt High Pressure Sodium wall light fixtures. When the lights are turned off, they frequently trip the GFCI breaker protecting the circuit. I have checked the circuit, ground resistance, and replaced the breaker. The breaker never trips during operation, only at shutoff. I suspect there is a small surge as the magnetic field in the ballast collapses that causes the nuisance trip. is there any way to correct this problem?