title: Putting large text in Texblock and ScrollViewer
body: <p>I have this PivotItem:</p>
  
  <pre><code>&lt;controls:PivotItem Header="Biografie"&gt;
         &lt;StackPanel&gt;
              &lt;ScrollViewer x:Name="textScroller" Margin="10,0,10,0"&gt;
                  &lt;TextBlock Text="{Binding Biography}"
                             TextWrapping="Wrap"/&gt;
              &lt;/ScrollViewer&gt;
          &lt;/StackPanel&gt;
   &lt;/controls:PivotItem&gt;
  </code></pre>
  
  <p>and in Biography I have large text (about 1575 chars). I can scroll with scrollviewer but I didn´t see all text. It just stop few sentences before end. I found that textblock don´t display more then 5000 chars or something like that but I have much less. Anyone know where can I have problem? Thanks</p>