Static pages should have the right links on the layout

While practising Michael Hartl's Rails tutorial, when I want to test the links. One test is failing with the following error message.

Error: "Static pages should have the right links on the layout" 

This can be fixed by putting "visit root_path" before  click_link "Sign up now!"

screen shot of the code is given below.
___________________

it "should have the right links on the layout" do
    visit root_path
    click_link "About"
    page.should have_selector 'title', text: full_title('About Us')
    click_link "Help"
    page.should # fill in
    click_link "Contact"
    page.should # fill in
    click_link "Home"
    visit root_path
    click_link "Sign up now!"
    page.should # fill in
    click_link "sample app"
    page.should # fill in
  end

____________________


 Useful Links :

• http://stackoverflow.com/questions/5361916/my-rspec-test-wont-pass-michael-hartls-rails-tutorial
• http://stackoverflow.com/questions/11732971/rails-link-to-not-found-by-capybara
• http://stackoverflow.com/questions/6701223/rail3-tutorial-testingchapter-5-click-link-error
• http://stackoverflow.com/questions/12242045/expected-css-title-hartls-tutorial-chapter-5-exercises