I just picked up my new Muddy Waters tele from the shop where I had it fret dressed and set up. It plays great, but when I bend a note on the G string I hear a very noticable pinging sound behind the nut. The pinging occurs twice - during the bend and as I'm easing the string back into position. If I damp the string with my right-hand index finger behind the nut and then repeat the bend with my left hand I don't hear anything. So I think its limited to just that third string. I'm sure my tech guy will take it back and fix whatever it is but can anyone offer some ideas as to what is causing this?