You might be able to repair it. As you did not answer my question about
which version of Publisher you are using, I will assume Pub 2003.
First back up your file in case something goes wrong. Click once on the
navbar to select it, and then on the wand that appears below it. That should
open a navbar options section to the left of your document. Under "Change
navigation bar" click on the Add, remove, and reorder links... The
Navigation Bar Properties will come up. Under Links, find your 5th page,
select it, and remove the link. Click Ok. The link should disappear from
your navbar if it appeared on any page. Then select the navbar, wand,
properties again, and click add link, select the page you want to add to the
navbar (the 5th page), and type in the Text to display, and click ok. The
navbar should now have a link for the 5th page.
DavidF