Word 2007 show combined revisions in one document

I combined several sets of revisions in one document and noticed a
peculiarity: when a word was replaced without deleting the space after the
word and inserting a new space, the deleted word would show up twice in the
combined-revisions document -- once before the inserted word and once after.
So it looked like this:
(replacing "dogs" with "cats" -- I'm USING caps to show the deleted word)

I like DOGScatsDOGS.

Where the space had been left in, it looked correct:

I like DOGS cats.

There was no problem in this respect with the individual redlined documents.
Is there some setting I can change on my computer that will correct this
problem?