If it doesn't leak before you pump it, then everything is usually good, and shouldn't leak after you pump it. By pumping it you are actually pushing the back of the bolt stem tighter against the powertube oring, so it should seal even better. Since it is doing it with different valves, it rules out a powertube scratch or bad oring being an issue. It might be an alignment issue that gets worst when you push the bolt back tighter against the valve.
Is the body sitting tight against the rail? Check that the body pim (where the grip frame screw holds the body on the rail) isn't bottoming out in the rail.
Is the body washer hole round, or has it gotten mushroomed? If it is mushroomed, file it out so that it is round again.
Except for the Automag in front, its usually the man behind the equipment that counts.