title: RelayCommand CanExecute behavior
body: <p>I have following command:</p>
  
  <pre><code>&lt;Button x:Name="bOpenConnection" Content="Start Production"
          Grid.Row="0" Grid.Column="0"
          Height="30" Width="120" Margin="10"
          HorizontalAlignment="Left" VerticalAlignment="Top" 
          Command="{Binding Path=StartProductionCommand}"/&gt;
  </code></pre>
  
  <p></p>
  
  <pre><code>StartProductionCommand = new RelayCommand(OpenConnection, CanStartProduction);
  
  private bool CanStartProduction()
  {
     return LogContent != null &amp;&amp; !_simulationObject.Connected;
  }
  </code></pre>
  
  <p><code>CanStartProduction</code> is checked only when I re-size the UI and not updated on the fly.
  Any idea why it's not updated every time they change the values ?</p>