During the conversion of RAW images the latest release of NX (1.1) occasionally places a black line in the image (sometimes but not always, and I haven't broken the code yet as to when/why it happens). I have loaded this same image several times; sometimes the line appears & sometimes not.

Look near the bottom left corner and you'll see a thin black horizontal line. It is NOT part of the image and other RAW converters do not cause this line to appear. It's something in NX - it appears just before the end of the loading step that reads "Rendering"; at the start of "Rendering" it is not there.