Article ID: 3139, created on Nov 30, 2007, last review on Apr 18, 2012
The reason for the problem is that this page does not have a title. So you should login to the Site Studio panel of the customer, go to some page that can bee seen in Site Map.
At the bottom of the page you can see links to the all other pages. Among them choose the page that doesn't show in Site Map. Go to the page settings and set the page title.