I have noticed when using a tablet while working in LR5 I have a dead spot in the upper part of the curve near the highlights portion. I thought it was just a result of my tablet being old and a cheaper model. I tested it with a new Intuos 5 Touch and had the same problem. I go to drag down or up on the upper part of the curve and it doesn't move or hangs up. It happens in all RGB channels also. Has anyone else had this problem or know why this happens? Thanks!