title: WPF Application Crash (Easy reproduction) - Is it a microsoft BUG?
body: <h2>Issue:</h2>
  
  <p>Our application crashes when a user type some text into the WPF TextBox.
  Please help! The easy 3 minutes reproduction appears below</p>
  
  <h2>Reproduction:</h2>
  
  <ol>
  <li><p>Register a WPF TextBox (m_textBox) TextChanged event to the method below</p>
  
  <pre><code>private void OnTextChanged(object sender, TextChangedEventArgs e)
  {
      // This line of code throws Unhandled exception when typing '^' char in 
      // the text box (in United "States-International" keyboard)
      m_textBox.Dispatcher.Invoke(DispatcherPriority.Normal, new SendOrPostCallback(Foo), null);
  }
  
  private void Foo(object state)
  {
      //Do nothing
  }
  </code></pre></li>
  <li><p>Change your keyboard to "United States - International"</p></li>
  <li><p>Run the application and type '^' twice in the TextBox</p></li>
  </ol>
  
  <p>Aplication will crash!!!!</p>