Thank you, Hotrod Gods!!! That stupid gasket washer was aluminum---its what came on the pan when I bought it new 5 years ago. I went down street and bought a 65 cent copper washer at PartSource, reinstalled the oilpan plug with new washer and torqued it down with a 1/2" drive hand ratchet. The leak is gone. I put the oil back into the engine and ran it for 20 minutes, and no more drips. I got lucky on this one.