Question: How can I remove the page titles so they don’t appear in the body of the page? (Duster and Twenty Twelve)

The tab in the top nav menu doesn’t have to be the actual page title, so here’s what you can do:

Edit the pages and delete their titles.
Go to Appearance>Menus and create a custom menu. Select your (now nameless) pages from the Pages module, click Add to Menu. Click the arrow at the right side of each page module to open it, type the title in the Navigation Label field. Click Save Menu, select the menu from the Theme Locations pulldown, click Save.
from > http://en.forums.wordpress.com/topic/duster-theme-double-headers?replies=5#post-616357