Unless "Lock zoom" is enabled, images will be CENTERED rather than not changing the position at all (particularly with "No Fit"). This is most easily noticed with images that are of the same resolution.
Don't know if it makes a difference, but I used a fresh copy of the XnView PortableApps version to test this.
v1.98: When Reset X/Y is unchecked, image gets centered
Moderators: helmut, XnTriq, xnview