Vaadin session timeouts Websphere Portal 7

Hi all,

we are currently developing application in Vaadin 6.8.x framework, with spring 3.1.
We are deploying application as a portlet in Websphere Portal 7.
Global session timeout for application server is set to “No Timeout”.
Application session is set to 120 minutes.

Currently, when user is working with application, Portal logs out user afer 120 mins regardless of activity or inactivity.
Has anynone solved this problem ?
Thank you.

Web.xml:

<?xml version="1.0" encoding="UTF-8"?>


Administration

Vaadin production mode
productionMode
true

<context-param>
	<param-name>contextConfigLocation</param-name>
	<param-value>/WEB-INF/applicationContext.xml /WEB-INF/services.xml /WEB-INF/security-config-jee.xml</param-value>
</context-param>

<filter>
    <filter-name>springSecurityFilterChain</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>

<filter-mapping>
	<filter-name>springSecurityFilterChain</filter-name>
	<url-pattern>/*</url-pattern>
	<dispatcher>REQUEST</dispatcher>
	<dispatcher>INCLUDE</dispatcher>
	<dispatcher>FORWARD</dispatcher>
</filter-mapping>

<listener>
	<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
	<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>

<login-config>
	<auth-method>BASIC</auth-method>
	<realm-name>SDMXAdministration authorized users</realm-name>
</login-config>

<servlet>
	<servlet-name>SDMXAdministrationServlet</servlet-name>
	<servlet-class>sk.anext.sdmx.administration.AutowiringApplicationServlet</servlet-class>
	<init-param>
		<description>Vaadin application class to start</description>
		<param-name>application</param-name>
		<param-value>sk.anext.sdmx.administration.SDMXAdministrationApplication</param-value>
	</init-param>
</servlet>

<servlet-mapping>
	<servlet-name>SDMXAdministrationServlet</servlet-name>
	<url-pattern>/SDMXAdministrationServlet/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
	<servlet-name>SDMXAdministrationServlet</servlet-name>
	<url-pattern>/VAADIN/*</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>

<session-config> 
    <session-timeout>120</session-timeout>
</session-config>		

<security-role>
	<description>Authenticated users</description>
	<role-name>ROLE_AUTHENTICATED</role-name>
</security-role>
<security-constraint>
	<display-name>Restriction</display-name>
	<web-resource-collection>
		<web-resource-name>all resources</web-resource-name>
		<url-pattern>/*</url-pattern>
		<http-method>GET</http-method>
		<http-method>POST</http-method>
		<http-method>HEAD</http-method>
		<http-method>DELETE</http-method>
		<http-method>PUT</http-method>
		<http-method>TRACE</http-method>
		<http-method>OPTIONS</http-method>
	</web-resource-collection>
	<auth-constraint>
		<description>Authenticated users</description>
		<role-name>ROLE_AUTHENTICATED</role-name>
	</auth-constraint>
	<user-data-constraint>
		<transport-guarantee>NONE</transport-guarantee>
	</user-data-constraint>
</security-constraint>
jdbc/SDMXAdminDS javax.sql.DataSource Container Shareable

portlet.xml:

<portlet>
    <portlet-name>SDMXAdministration</portlet-name>
    <display-name>SDMXAdministration</display-name>
    
    <portlet-class>org.apache.portals.bridges.common.GenericServletPortlet</portlet-class>
	<init-param>
	      <name>ViewPage</name>
	      <value>/SDMXAdministrationServlet</value>
	</init-param>
    
    <!--
      To enable displaying multiple Vaadin portlets on a page,
      they should all use the same widgetset. In that case, the
      widgetset can be configured on the portal level (parameter
      vaadin.widgetset) or here for each portlet.
    -->
    <!--
    <init-param>
        <name>widgetset</name>
        <value>com.vaadin.portal.gwt.PortalDefaultWidgetSet</value>
    </init-param>
    -->
    
    <!-- Supported portlet modes and content types. -->
    <supports>
        <mime-type>text/html</mime-type>
        <portlet-mode>view</portlet-mode>
        <!-- <portlet-mode>edit</portlet-mode> -->
        <!-- <portlet-mode>help</portlet-mode> -->
    </supports>
    
    <!-- Not always required but Liferay uses these. -->
    <portlet-info>
        <title>SDMXAdministration</title>
        <short-title>SDMXAdministration</short-title>
    </portlet-info>
</portlet>