How about Options/Misc 2/Windows options:
Centre window when loading new image
=======================
That's not the same thing. You are confusing centering the
picture with centering the window. When you have the option
set for the window to vary in size according to picture pixel
dimensions, then your method will work ... IF you are
satisfied with the window continually changing size, and
being wildly distracted by whatever underlying desktop is
exposed. (other open programs, wallpaper, etc)
For me .. I vastly much rather prefer that my viewer programs
remain fully maximized to cover all of that underlying stuff,
and to present a pleasing solid black background with all
pictures (regardless of size) centered in the middle of the
blackness. All other similar programs I have used do this ..
but, not IrfanView.