I am getting a strange rattling coming from what seems to be somewhere on the neck, when I play the first fret on the E. It only happens on this fret, and it's not rattling from the fret. I tightened all tuner bolts, checked to see if the truss rod nut was loose, and even tapped on the back of the neck and it doesn't seem to be coming from any of these places. I thought it might be the nut, so I put a finger of the nut slot while I pressed down on the first fret with another finger to see if it would stop and this didn't work either. Any idea what else it could be? It's not overly loud, and I'd say it's more audible unplugged than plugged (unless the tone is cranked).