Kann nicht ausgeführt werden, Vaadin-Projekt in Eclipse Juno mit Tomcat 7: throws ClassNotFoundException

Habe ich eine basic-Vaadin-Projekt (von der Vorlage, die ich noch nicht bearbeitet, die den code selbst). Ich bin mit:

• Vaadin 6.8.9
• Tomcat 7
• Eclipse Juno

Tomcat wirft die folgende stack-trace:

    HTTP Status 500 - Failed to load application class: com.example.addressbook.AddressbookApplication

    type Exception report

    message Failed to load application class: com.example.addressbook.AddressbookApplication

    description The server encountered an internal error that prevented it from fulfilling this request.

    exception

    javax.servlet.ServletException: Failed to load application class: com.example.addressbook.AddressbookApplication
        com.vaadin.terminal.gwt.server.ApplicationServlet.init(ApplicationServlet.java:71)
        org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
        org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
        org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:947)
        org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
        org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1009)
        org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
        org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
        java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        java.lang.Thread.run(Unknown Source)

Meine web.xml die Datei lautet wie folgt:

    <?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"        xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-       app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee        http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
      <display-name>AddressBook</display-name>
      <context-param>
        <description>Vaadin production mode</description>
        <param-name>productionMode</param-name>
        <param-value>false</param-value>
      </context-param>
      <servlet>
        <servlet-name>Addressbook Application</servlet-name>
        <servlet-class>com.vaadin.terminal.gwt.server.ApplicationServlet</servlet-class>
        <init-param>
            <description>
            Vaadin application class to start</description>
            <param-name>application</param-name>
            <param-value>com.example.addressbook.AddressbookApplication</param-value>
        </init-param>
      </servlet>
      <servlet-mapping>
        <servlet-name>Addressbook Application</servlet-name>
        <url-pattern>/*</url-pattern>
      </servlet-mapping>
      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
      </welcome-file-list>
    </web-app>

Ich weiß nicht, was das problem ist... Anregungen sind wir sehr dankbar.
Danke.