paragraph spacing changes when inserting

[Jill B]

When I insert a word document at the end of another word document, the
paragraph spacing changes. The master documents are correct and insert fine
into a blank document but when joined, word has a mind of it's own and
changes the spacing.

 

[grammatim]

What happens to the spacing? Is it in the added document, the host
document, or both? Version of Word? How do you do the inserting?