<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

  <title><%= page_title %></title>

  <%= stylesheet_link_tag 'admin/reset', :media => 'screen' %>
  <%= stylesheet_link_tag 'admin/screen', :media => 'screen' %>
  <%= yield :stylesheet -%>

  <%= javascript_include_tag 'admin/application' %>
  <%= yield :javascript -%>

</head>

<body>

  <div id="header_wrapper">

    <div id="header">
      <div class="left">
        <%= header %>
      </div>
      <div class="right">
        <%= login_info %>
      </div>
      <div class="clear"></div>
    </div>

  </div>

  <div id="wrapper">

    <div id="content_wrapper">

      <div id="content">
        <%= display_flash_message %>
        <%= yield %>
      </div>

      <div id="sidebar">
        <%= yield :sidebar %>
      </div>

      <div class="clear"></div>

    </div>

  </div>

  <div id="footer_wrapper">

    <div id="footer">
      <%= typus_block :location => 'shared', :partial => 'footer' %>
    </div>

  </div>

</body>

</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

  <title><%= page_title %></title>

  <%= stylesheet_link_tag 'admin/reset', :media => 'screen' %>
  <%= stylesheet_link_tag 'admin/screen', :media => 'screen' %>
  <%= yield :stylesheets -%>

  <%= javascript_include_tag 'admin/application' %>
  <%= yield :javascripts -%>

</head>

<body>

  <div id="header_wrapper">

    <div id="header">
      <div class="left">
        <%= header %>
      </div>
      <div class="right">
        <%= login_info %>
      </div>
      <div class="clear"></div>
    </div>

  </div>

  <div id="wrapper">

    <div id="content_wrapper">

      <div id="content">
        <%= display_flash_message %>
        <%= yield %>
      </div>

      <div id="sidebar">
        <%= yield :sidebar %>
      </div>

      <div class="clear"></div>

    </div>

  </div>

  <div id="footer_wrapper">

    <div id="footer">
      <%= typus_block :location => 'shared', :partial => 'footer' %>
    </div>

  </div>

</body>

</html>

Use plural on head blocks.
Use plural on head blocks.
