I have been thinking all the time that this is a screen-resolution and paper size thing - most monitors had a resolution of 800 x 600 (1: 0.75) back then and DIN A4 297mm x 210 mm (1 : 0.71) - so 1000 x 800 is close that - but I may be totally wrong ?

Glad that this issue comes up again - I almost forgot about it. I had the same problems already when I created ripples around poles and noticed the left shift. I tried to minimize it but could not get rid of the left shift - so you still notice it even on my images...