Thanks for replying Ulo.
An example of this effect would be that a paragraph of 9 lines in the original will need to go into the 10th line in the copy. It's as if the character spacing is slightly greater in the copied version.
However, I have rechecked that all the parameters are the same in both versions:
in particular, character spacing in both versions is 'normal'; the line spacing in both versions is '1.5'; margins are the same; and the Header and Footer margins are the same also.
Regards dms997