Window / Components not visible


I made a servler forward from my application to a HttpServlet. Unfortunately when I start the application no components are visible in the browser.
If I take away the servlet forward all components are visible. There is no problem with
the forwarded servlet everything works fine (I debugged this part).

If I refresh the browser all components appear. Is that a bug or did I make something wrong?

Here is the init method of the application:

public void init()

	mainWindow = new Window("Paxwebsale");
	Label label = new Label("Hello Vaadin user");
	Button button = new Button("Ok");
	ApplicationContext ctx = getContext();
	WebApplicationContext webCtx = (WebApplicationContext) ctx;
	servletContext = webCtx.getHttpSession().getServletContext();
	RequestDispatcher dispatcher = servletContext.getRequestDispatcher("/servlet/ch.pax.websale.server.ServletConnect");
	try { dispatcher.forward(request, response); } 
	catch (ServletException e) { e.printStackTrace(); } 
	catch (IOException e) { e.printStackTrace(); }

B. Call

Here are additional informations:

if I make a forward call in the init() method
to a servlet of another project (older programm) → it works

if I make a forward call in the init() method
to a http servlet of my vadin project and
from this vadin project a forward to a servlet of another project (older programm)-> it doesn’t work