One of the hardest parts of doing SEO work is the moving target that Google creates with their algorithm changes. Although Google will not say how often they change this formula (a formula that determines how they provide results), there have been changes over the last few months that made us stand up and take notice.
Google now indicates they are more likely to pick keywords from the pages content as opposed to headers (H1 headers as an example), menus, etc. Over the past year Google has emphasized keywords being used (appropriately) in your pages content thinking this will ultimately deliver the best results for Google users.
Bottom Line
Write your pages content with your keywords in mind and worry less about page titles, headers, etc. Those things are still important but not near as important as providing the very best content possible and having people link to that page because they find it valuable.