title: TextBlock with multiple <Run> spacing
body: <p>Given a formatted text block in Windows Phone 7.1 project:</p>
  
  <pre><code>&lt;StackPanel Orientation="Horizontal"&gt;
      &lt;TextBlock Foreground="DarkGray" VerticalAlignment="Bottom" Margin="0,0,0,8"&gt;
              &lt;Run Text="total length "/&gt;
              &lt;Run Text="{Binding TotalHours}" FontSize="48"/&gt;
              &lt;Run Text="h "/&gt;
              &lt;Run Text=":" FontSize="48"/&gt;
              &lt;Run Text="{Binding TotalMinutes}" FontSize="48"/&gt;
              &lt;Run Text="m "/&gt;
      &lt;/TextBlock&gt;
  &lt;/StackPanel&gt;
  </code></pre>
  
  <p>It is being previewed correctly in VS designer:</p>
  
  <p><img src="https://i.stack.imgur.com/pezdJ.png" alt="vs text block"></p>
  
  <p>It is already looking not the way I want in Blend:</p>
  
  <p><img src="https://i.stack.imgur.com/uQyVQ.png" alt="blend text block"></p>
  
  <p>It looks just as in Blend (good job Blend team) in emulator and a real device. </p>
  
  <p>What adds those spaces before and after big 8 and 45? </p>
  
  <p>How can I force my layout to look correctly (like in VS designer)? </p>