I recently got NX as a bundle with my D700. Previously I've been using ACR but it seems sensible to get familiar with the Nikon software. Naturally I haven't read much of the helpfile documentation... hoping to get familiar with the feel of the program and then fill in the gaps by reading the helpfile as required.
The first thing I tried was to open a NEF shot using the 14-24 2.8. I rotated this file into portrait orientation (got camera set to not activate the rotation flag in the exif - for a reason). Then I selected the adjust/correct/distortion menu option to open the distortion control dialog. My first surprise was that there is a default of 10 for the barrel-correction slider - at first I thought that there might be a lens database that had identified this lens (and why isn't there?) until I noticed the default setting. Odd.
My next surprise was more significant. The instant I clicked on the vignette correction slider the preview image squashed by about 50% vertically and then immediately rotated 90deg. Every time I reset the orientation and attempted to use this slider the same thing happened. I then gave up in disgust and wrote this.
Am I labouring under some terrible misunderstanding about how this application works or is it buggy? These distortion correction functions are bog-standard so I didn't expect to encounter any significant learning curve.
Go to Edit -> Preferences -> General and make sure the option 'Keep all steps active in Edit List' is checked.
Does this help?