title: WPF Combobox is changing source via SelectedValue when ItemsSource is loaded
body: <p>I have this combobox in my WPF window.</p>
  
  <pre><code>&lt;ComboBox DisplayMemberPath="Description" SelectedValuePath="ID" ItemsSource="{Binding Source={StaticResource CvsPrinters}}" SelectedValue="{Binding CheckPrinterID}" /&gt;
  </code></pre>
  
  <p>My problem is that when loading the window, the SelectedValue binding is causing my source data to change to the first item in the ItemsSource, instead of setting the Combobox's SelectedValue to the appropriate item in the ItemsSource.</p>
  
  <p>The CheckPrinterID is from a listview selection datacontext, and this problem only occurs to the item initially selected in that listview on load.  When I select another item in the listbox, the combobox correctly selects the proper item and all is fine, but unfortunately my initial item has been updated and is now incorrect.</p>