Image via Wikipedia
So Jerrold Green1 figured it out:
Sometimes in the process of importing from Word, page numbers are improperly converted to Master Objects or Background Objects. Go to Format > Advanced > Make Master Objects Selectable. Then, with the cursor in the Margin of the document, press the Command Key (Cursor changes to an Arrow) and drag the cursor diagonally across the page number to select it. Then press the Delete key and the number should be gone. You need to check carefully to make sure that you have eliminated all the instances. There may be one per Section.
via Apple – Support – Discussions –.