How to make enhance feature work

[Leafields]

I have recenty installed XnView 1.97. If I use "enhance" features such as "enhance focus", it shows the change in the small picture on the right. I tick the "apply to image", close the window, save the picture saved, return to browser view and the picture has not changed.
I must be doing something wrong. Any suggestions gratefully received.
Confused of Leafields

[marsh]

The changes can be subtle, so you may have to view hi-res image at original size to see them (zoom=100%).