title: Binding ribbon text box IsEnabled to checkbox IsChecked not working
body: <p>Here is the sample XAML:</p>
  
  <pre><code>...
  &lt;ribbon:RibbonTab Header="MyTab"&gt;
    &lt;ribbon:RibbonGroup Header="Blah"&gt;
      &lt;ribbon:RibbonTextBox x:Name="MyTextBox" 
                            IsEnabled="{Binding IsChecked, ElementName=MyCheckBox}" /&gt;
      &lt;ribbon:RibbonCheckBox x:Name="MyCheckBox" Label="some text" /&gt;
    &lt;/ribbon:RibbonGroup&gt;
  &lt;/ribbon:RibbonTab&gt;
  ...
  </code></pre>
  
  <p>For some reason, the text box stays disabled regardless of whether or not the check box is checked. Why is the binding not working properly?</p>
  
  <p>You can add the above code minus the elipses at the top and bottom to a boiler plate WPF ribbon project and see if you can figure out what's wrong. I see no binding error diagnostics, for example.</p>
  
  <p><strong>Update</strong>: If a regular <code>TextBox</code> is substituted for the <code>RibbonTextBox</code>, the behavior becomes correct. I conclude that there must be some issue with binding the IsEnabled property of a <code>RibbonTextBox</code>.</p>
  
  <p><strong>Freaky update #2</strong>: Creating a basic <code>RibbonTextBox</code> and setting its <code>IsEnabled</code> property to <code>True</code> creates a disabled RibbonTextBox. What gives?</p>
  
  <p>I have submitted a <a href="https://connect.microsoft.com/VisualStudio/feedback/details/723134/the-isenabled-property-of-the-microsoft-ribbon-for-wpf-ribbontextbox-control-does-not-function-properly#details" rel="nofollow">bug report</a> on Microsoft Connect to further pursue this issue.</p>
  
  <p><strong>Final update</strong>: It's <a href="http://connect.microsoft.com/VisualStudio/feedback/details/633097" rel="nofollow">fixed in WPF 4.5</a>.</p>