Rick:
It's likely that your inserted document used a paragraph style (say Normal,
or Body Text) that is also defined in the host document. The definition of
that style in the host document would be used, and may be different.
It's probable that the Spacing Before, Spacing After, or Line Spacing is
different in the host document.
As a quick check, open the host document and the source of the inserted
document. In each document, position the insertion point in a body text
paragraph (might be any style name, but the one used for the bulk of the
paragraphs in your document) and click Format > Paragraph. Compare the
settings.
You can apply manual formatting to all the body text paragraphs in the
inserted file to make them match the settings in the original source file.
But THIS IS A BAD PRACTICE; even though it's quick it's dirty.
Better solutions would be to change the definition of the style in the host
document so it matches the definition used in the inserted document OR rename
the style in the source of the inserted document, so that when you insert it
you also insert the unique style names and their related style definition.
Changing the style definition in the host document will make ALL the body
text in that document look slightly different. If you can live with that, the
easiest way to do this is to click Format > Style, then click the Organizer
button. Use the Close/Open File button to position the source document in the
left pane and the host document in the right pane. Select the desired styles
in the left pane and click Copy.
To rename the styles in the source document, click Format > Style, select
the style then click Modify. Type the new name. E.G. Body Text might become
Body Text Insert.
Note that you cannot change the style name of a built-in style such as
Normal. If that's what's being used, you'll have to define a new custom style
with a unique name but the same properties as Normal, then use Find and
Replace (with the More button clicked) to replace the Normal style with your
custom style on all the paragraphs to which it's applied.
IF you're using Word 2003 or 2007 there may be faster, easier ways to
accomplish these ends.
Bear