Dynamically change position of Axes

I’m trying to control the position of the Axes (vtkOrientationMarkerWidget).
In our interface, there should be an option to change the position with 4 possible values: Bottom left, bottom right, top left, top right).
I know that I can set the position of the vtkOrientationMarkerWidget with the call to setViewport, but that seems to only work the first time.

I’m using VTK 7.1.1 with Visual Studio 2010.
Here a snippet of my code:

// initialization, in constructor of the class that handle the vtkRenderer. All with m_ are properties of     the class.
// Axes actor
m_axesActor = vtkSmartPointer<vtkAxesActor>::New();
// Orientation marker that synchronizes its orientation with the camera position.
m_widget = vtkSmartPointer<vtkOrientationMarkerWidget>::New();
m_widget->SetInteractor(m_renderWindowInteractor); // vtkSmartPointer<vtkRenderWindowInteractor>, interactor of the render window.
m_widget->SetOrientationMarker( m_axesActor );
m_widget->SetViewport(0, 0, 0.4, 0.4); // bottom left, works OK.
m_widget->InteractiveOff(); // i don't want to be interactable...
// After, in method to change the position:
void changePosition(int position)
// This has no effect
	m_widget->SetViewport(0, 0, 0.4, 0.4);
else if (position == AXES_POSITION_BOTTOM_RIGHT)
	m_widget->SetViewport(0.6, 0.6, 1.0, 1.0);
else if (position == AXES_POSITION_TOP_LEFT)
	m_widget->SetViewport(0, 0.6, 0.4, 1.0);
else if (position == AXES_POSITION_TOP_RIGHT)
	m_widget->SetViewport(0.6, 0.6, 1.0, 1.0);
	// more code follows, with calls to redraw and sort...

Thank you.

Finally I solved it by myself.
The secret was to call SetEnabled(0) before changing the position with SetViewport. Then you should call SetEnabled(1).