I just started playing with a Dunlop Max 200G. I hit against a wall for about 3 hours straight yesterday, and although I don't have it now, I was starting to get pain in that C-shaped area between my index finger and thumb--more towards the butt of the thumb. I noticed that the pain would really start to pound when I was hitting forehand volleys with the continental grip. What could be causing this? I just put on a new, thinner leather grip. Possibly it's because the grip is a bit undersized? Or maybe I'm going TOO continental on those forehand volleys? Either way, the Dunlop MAX 200G, the forehand volley continental grip, and the thinner replacement grip are ALL sort of new things to me.