In VC++ 2013, dialog boxes damage PictureBox contents (drawing)

I cannot find how to protect a drawing in a PictureBox control from being corrupted (wiped out) when I call a dialog to save the form or print it out. The form is saved or printed out OK, but the dialogs wipe out most of the PictureBox drawing after they leave. Yet the buttons and progress bar on the form are restored OK -- so there must be a way to 'protect' the PictureBox drawing as well. How is it done? I cannot find how to protect a drawing in a Pic