title: Binding doesn't respond to PropertyChanged
body: <p>I have a model and a view-model for a Window and I'm stuck with view.<br />
  The view has a control that has the following Content:</p>
  
  <pre><code>&lt;TextBlock Text="{Binding Title}" [...] /&gt;
  </code></pre>
  
  <p>The data-context is the view-model, which has a <code>Title</code> property of type string.</p>
  
  <p>The issue is that even when the value changes (and I can see it does through the debugger) and <code>PropertyChanged</code> is called for the <code>Title</code>, the <code>TextBlock</code> doesn't change (it stays empty).</p>
  
  <p><em>To confirm this I've actually called an update method on every mouse press.</em></p>
  
  <p>I've heard sometimes the binding in <code>TextBlock</code>s are bugged so I've also tried a Label but it didn't work. Any suggestions? If there's any code you want to see please tell me in the comments (the whole thing is pretty big).</p>
  
  <p><a href="http://pastebin.com/9M9MZsxv" rel="nofollow">ViewModel</a><br />
  <a href="http://pastebin.com/Y9aTBw75" rel="nofollow">Code-behind for the View.</a></p>
  
  <p><strong>To be clearer: <code>Window</code> is my model, and not WPF's Window!</strong></p>