I noticed that when I add any adjustment layer like Curves or Brightness and contrast, etc., on the left hand side of the layer, instead of seeing the corresponding adj layer thumbnail, I see a half moon circle. Besides it ofcourse I see the mask thumb nail. How to get back the original thumbnail of the adj layer selected? Second issue I see is, On the mask thumb nail if I paint with a brush with Black as foreground or invert the mask, paint with white brush doesn't see the masking happening. Any help appreciated. Thanks.