Anne,

Thanks for your reply.

I checked the line-spacing in both documents and they were the
same.  I don't think the problem related to line-spacing per se
because not only did the line-spacing appear greater Doc2, but
also the SpaceBefore and SpaceAfter headings also appeared
greater in Doc2 (even though all these properties were the same
in Doc1 and Doc2).

In fact, I checked everything I could think of!  Not only did I
import the styles from Doc1 to Doc2 and verified that they were
the same in both docs, but I clicked into each heading and
paragraph in Doc2 and verified in the Format > Paragraph dialog
that the formatting applied by the styles was the same.  Yet the
Doc2 was stretched downwards.

Thanks for the tip on replacing styles.  I am familiar with Find
and Replace and the More button, so your explanation is fine.  I
assume you suggested replacing the Normal style with the Normal
style as a means of re-applying the Normal style where
appropriate.  (If you didn't mean that, perhaps you'd
elaborate?)  I fact I did reapply appropriate styles manually to
a few paragraphs and used CTRL-SPACEBAR to remove any possible
extraneous formatting, but all to no effect.

Earlier today I solved my problem by reconstructing the Doc2.
However, see Stefan's contribution to this conversation for the
diagnosis of my problem and my reply to him for an account of
what I did (if you're interested).

Thanks again for your time and contribution.
Geoff