You may want to clean the side of the case very carefully and look for leaks other than the pan gasket. There are several areas on the sides of the case that are sealed by "O" rings. If those "O" rings leak the fluid runs down to the pan/case joint and it looks like the pan gasket is leaking. I just had to to replace the B2 Reaction Valve "O" ring for a leak that appeared at first to be a pan gasket leak. I had to drop the valve body, etc. A real PITA with the transmission in the car.