has this happened to anyone? Got a chance to play royal county down last week. After hitting my driver, my caddie noticed a vibrating sound coming from the head. It was like a buzz - almost tuning fork like for over two minutes. Couldn't figure what it was. Happened once more during the round and then stopped. Have played 3 rounds with it since then and not been able to replicate it. Tested the screws after getting home and they seemed fine. Any ideas?