I've been using NX Studio for a few weeks and am really pleased with it. There is no better approach to create my NEF files, in my opinion. So, there are some bugs...but that's to be expected with a version 1.0!
As a result, if I hit QUIT, the modifications made to my previous image are lost, yet the program stays open. When I clicked SAVE, the same thing happened.
This is simply for reference...now I copy all of my changes and paste them when it happens again...exporting all settings is also a good alternative.