title: Custom MFC control prevents dialog creation
body: <p>I have a custom MFC control, subclassing CWnd. Other than providing OnPaint and PreSubclassWindow implementations, it overrides no default functionality and does nothing weird in construction except registering a window class in the constructor.</p>
  
  <p>The control is added to the dialog using the dialog editor to add a custom control.</p>
  
  <p>The dialog worked when it was a simple modal dialog deriving from CDialog, but we have code which calls CWnd::CreateDlgIndirect to instance dialogs and this fails with the custom control... but works if the custom control is removed from the resource template.</p>