Session Expired Problem

Hello Community,

my Vaadin7ExampleUI works in eclipse with the vaadin-plugin perfekt, also the embedding in jsp. But if I try to embed it on my own eclipse web project I get the error message: "
Session Expired
Take note of any unsaved data, and click here to continue."
What am I doing wrong?

web.xml:

[font=Courier New]
[size=2]


240

[…]

Vaadin7Example com.vaadin.server.VaadinServlet UI vaadin.Vaadin7exampleUI Vaadin7Example /V/Vaadin7Example/app/* Vaadin7Example /V/Vaadin7Example/VAADIN/* ... [/size] [/font]

jsp:

[font=Courier New]
[size=2]

Vaadin7Portlet
... [/size] [/font]

Dennis