title: Property bound to radcombobox not updated after item selected
body: <p>After selecting an item from a combobox, the property attached does not get updated as expected.  It's a noob error but I'd like to know what I'm doing wrong, please.</p>
  
  <p>XAML:</p>
  
  <pre><code>&lt;telerik:RadComboBox x:Name="cboFinish" ItemsSource="{Binding}" Text="{Binding finish}" TextSearch.TextPath="theFinish" IsEditable="True" &gt;
  </code></pre>
  
  <p>Property:</p>
  
  <pre><code>    Private _finish As String
  Public Property finish As String
      Get
          Return _finish
      End Get
      Set(value As String)
          _finish = value
          NotifyPropertyChanged("finish")
      End Set
  End Property
  </code></pre>
  
  <p>In the dropdown closed event of the combo, I have to assign the property the value of cboFinish.Text to update the property to the new selection.  This code shouldn't need to be done, does it?<br>
                  thisOrderFinish.finish = cboFinish.Text</p>
  
  <p>I thought that was the job of INotifyPropertyChanged.</p>
  
  <p>Comboboxes seem to be the only control where I've noticed this behavior.  Textbox properties updated as expected.  </p>
  
  <p>Thanks for your help.</p>
  
  <p>Edits:
  Combobox binding:</p>
  
  <pre><code>        Dim dt As New DataTable
          da.Fill(dt)
          cboFinish.ItemsSource = dt.DefaultView
  
          cboFinish.IsTextSearchEnabled = True
          cboFinish.StaysOpenOnEdit = True
  </code></pre>
  
  <p>Modified XAML:
                              </p>