RadPageView in BackStageMode loses its content when user changes the theme from the Listbox, placed into BackStageView.
For example, user choose Office2010Black or Office2007Black or HighContrast and BackStage view appears empty

Workaround: all recursively the UpdateLayout method for all RadControls in the form

private void RefreshAll()
{
    foreach(Control control in this.Controls)
    {
        RefreshAllControls(control);
    }
}
 
void RefreshAllControls(Control ctrl)
{
    foreach (Control control in ctrl.Controls)
    {
        RadControl radControl = control as RadControl;
        if (radControl != null)
        {
            radControl.RootElement.InvalidateMeasure(true);
            radControl.RootElement.UpdateLayout();                   
        }
        RefreshAllControls(control);
    }
}