title: WPF SaveFileDialog DefaultExt ignored?
body: <pre><code>var dlg = new SaveFileDialog();
  dlg.FileName = "graph";
  dlg.DefaultExt = ".bmp";
  dlg.Filter = "PNG|*.png|DOT|*.dot|Windows Bitmap Format|*.bmp|GIF|*.gif|JPEG|*.jpg|PDF|*.pdf|Scalable Vector Graphics|*.svg|Tag Image File Format|*.tiff";
  </code></pre>
  
  <p>The extension always defaults to <code>.png</code>. It seems the <code>DefaultExt</code> is ignored if there is a <code>Filter</code>; then it just defaults to the first option in the list.</p>
  
  <p>Is there a way to force it to actually respect the default ext?</p>