After dragging a report viewer control from the Visual Studio toolbox to the surface of a Windows Form, the viewer is added to the component tray but it is not added to the Controls collection of the form. Thus, the viewer is not displayed when running the application.
Also, some properties of the report viewer, such as the ReportSource property, are not serialized properly after being modified through the Visual Studio properties window.
Currently, one can work around these issues by manually editing the InitializeComponent component method of the form's .Designer.cs file.