The only thing I can think of that would cause formatting to change upon
opening those documents would be if "Automatically update document styles"
is enabled, and the style-based spacing is set to triple spaced in the
default document template (usually Normal.dotm unless you've set it to
somethign else). Since this is set on a per document basis, I don't know of
any way of turning it off for any given document, since the document needs
to be opened to turn it off, and once it's open, it's already too late to
turn it off, because the damage is already done
My first stab would be to rename Normal.dotm so that Word creates a new one
when Word is next opened. At the very least, since Word doesn't create
triple spacing when it creates a new Normal.dotm, that should prevent that
particular aspect of the problem from occurring. You might also want to edit
the new Normal.dotm so that the formatting contained in whatever styles are
being applied to the converted documents conform to your expectations and
needs. That way, when a document with "Automatically update document styles"
is opened, the formatting that is automatically applied wouldn't be so much
at odds with what you want.
Once open, you can turn "Automatically update document styles" in any
particular document by clicking the Developer tab, Document Template tool,
then removing the check next to "Automatically update document styles".
I hope this helps...
