Leaky sink drain again

Just stripped the sink and replaced the faucet and drain. Now the drain leaks. It is the drain that comes with the faucet. It is a Moen. This is a two piece drain. I used plumbers puddy were it comes into the sink and there is a tapered rubber gasket on the bottom and a nut. What happens is water leaks out what appears to be the threads on the large nut on the bottom. I believe this means the seal is not sealing and water is allowed to collect in the over-flow area and run down the threads. I installed a sink a few years ago, same brand faucet and had the same results. That sink was new and I never could seal the over-low area so i just plugged the over-flow holes. Also I ended up silicone between the drain and sink to stop the leak into the over-flow area. Any ideas really appreciated. Thanks, J