title: TextBlock does not display all Text
body: <p>I am new to this forum and new to windows phone 8 development.</p>
  
  <p>I have below code </p>
  
  <pre><code>&lt;Grid x:Name="LayoutRoot" Background="#EEF8E5" Loaded="LayoutRoot_Loaded"&gt;
          &lt;Grid.RowDefinitions&gt;
              &lt;RowDefinition Height="Auto"/&gt;
              &lt;RowDefinition Height="*"/&gt;
              &lt;RowDefinition Height="Auto"/&gt;
          &lt;/Grid.RowDefinitions&gt;
          &lt;!--TitlePanel contains the name of the application and page title--&gt;
          &lt;TextBlock x:Name="ApplicationTitle" FontWeight="Bold" Padding="20,0,0,0" Grid.Row="0" Text="فرآن کریم"/&gt;
  
          &lt;ScrollViewer  Grid.Row="1" VerticalScrollBarVisibility="Visible"
                        x:Name="Scroller"  VerticalContentAlignment="Top" &gt;
              &lt;Grid x:Name="ContentPanel" Margin="20,0,0,0"&gt;
                  &lt;Grid.RowDefinitions&gt;
                      &lt;RowDefinition Height="70"&gt;&lt;/RowDefinition&gt;
                      &lt;RowDefinition Height="*"&gt;&lt;/RowDefinition&gt;
                  &lt;/Grid.RowDefinitions&gt;
                  &lt;TextBlock x:Name="txtBismullah" FontSize="40" HorizontalAlignment="Center" Grid.Row="0"&gt;&lt;/TextBlock&gt;
                  &lt;TextBlock x:Name="txt" FontSize="40" Grid.Row="1" TextWrapping="Wrap" /&gt;
              &lt;/Grid&gt;
          &lt;/ScrollViewer&gt;
  
          &lt;Grid Grid.Row="2" Background="Silver" VerticalAlignment="Bottom"&gt;
              &lt;Button Content="1" Width="100" BorderThickness="0" VerticalAlignment="Top" Click="Button_Click"&gt;&lt;/Button&gt;
          &lt;/Grid&gt;
      &lt;/Grid&gt;
  </code></pre>
  
  <p>and c#</p>
  
  <pre><code>string readData()
          {
              string suraIndex = string.Empty;
              int counter = 1;
              for (int i = 0; i &lt; 40; i++)
                  suraIndex += counter++ + Environment.NewLine;
              return suraIndex;
  
          }
  </code></pre>
  
  <p>and finally </p>
  
  <pre><code>txt.Text += readData();
  txt.Text += " I am Here";
  </code></pre>
  
  <p>The prob is, It does not show all the text, It shows only upto 35 (while there is a scroll because of scroller) but no text is displayed.</p>
  
  <p>I dont know what is wrong with textblock and or may be its height, though it's set to Auto.</p>