leaking header bolt

I have fluid showing up on my starter. It appears as though it is comming from the last exhaust port on the drivers side. I put RTV on the end header bolts when I installed. Last night, I pulled the bolt on the rear driver's side and put RTV on it again. I let it set 24 hours and drove the car tonight. It still appears to be leaking. Anybody have any secrets to get it to stop?