Undo once (or cmd-z), and you'll get what you wanted.
To prevent this in the future:
With the cursor in a problematic word, click on Format | Style. Click
Modify. UNCHECK automatically update, and CHECK add to template. OK
everything and exit back to document. If the problem occurs in other
documents, repeat the same procedure.
The problem is that a style is set to automatically update. It is
possible, depending on how the resume is formatted, that you will need
to repeat this procedure for more than one style in the same document.
Full explanation (written for WinWord) here:
http://word.mvps.org/FAQs/Formatting/WholeDocumentReformatted.htm
(hit refresh a few times if using safari)
