Did you make sure the old gasket was not stuck to the fitting? This happened to me but I caught it before I put the new filter on. I always check the old filter and the block fitting. Maybe you got some dirt on the gasket during install. Another obvious is did you lube the gasket with oil before install?

I cannot think of any other reason it would be leaking. All the oil passes inside the gasket ring.

__________________
George

2011 Ranger Sport 4 door SuperCab 4X4 Oxford White, 4.0 Auto Mods: XLT Carpet, Pin Stripes, Clear Corners, Extang Revolution Tonno, LineX, Pre Key mod, tailgate lightbar, cab lights, Muth heated signal mirrors
2008 Ranger Reg Cab 4X2 Redfire Vulcan Auto Mods:FX4 body color grille, Sport aluminum wheels, Extang Revolutioin Tonno, color matched bed liner, tailgate lightbar TRADED