I hesitate to offer you advice since I'm not nearly as good a golfer as you are but when you said that you were swinging softly it rang a bell with me. I was having trouble hitting shots especially with my 5 wood last fall and it seemed like the more I tried to just swing easy the worse it got. Finally I just started to swing hard without overswinging and I started really tagging the ball. My theory is that I have a tendency to pull up to follow the ball and if I my swing is too slow I have started to lift my head whereas if I swing harder I make contact before my head begins to pull up. I don't know if this will help but you might give it a try.