It seems like Vaadin Push made the session expired message never appear

Hello,

I have a web app that push was added to. It seems like about that time the session expired window stopped appearing. Instead the app is unresponsive to anything the user does except a page refresh.

In the javascript console there are messages saying that the wigitset knows that the server is out of session in various ways. There are a lot of them right now. I'm not sure which ones are helpful. Here are some of the messages it logs:

com.mvsc.czrmis.vaadin.widgetset.CombiningWidgetSet-0.js:6510 POST http://localhost:8080/CZRMIS_MAIN/HEARTBEAT/?v-uiId=0 410 (Gone)

WARNING: Heartbeat request returned 410com.vaadin.client.ApplicationConnection

SEVERE: Session expired: null

com.vaadin.client.communication.Heartbeat
INFO: Setting hearbeat interval to -1sec.

com.vaadin.client.communication.MessageSenderWARNING: Trying to send RPC from not yet started or stopped application

I have to use my own implementation of AtmosphereInterceptor to work with the application's framework. I've cut session timeout and heart beat to 1 minute for troubleshooting. Here are some code snipits:
web.xml

<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
  <session-config>
    <session-timeout>1</session-timeout>
  </session-config>
</web-app>

Vaadin servlet

@WebServlet(name = "servlet", urlPatterns = {"/*"}, asyncSupported = true,
  initParams = { @WebInitParam(name = "org.atmosphere.cpr.AtmosphereInterceptor",
  value = "com.myorg.MyAtmosphereInterceptor")})
  @VaadinServletConfiguration(heartbeatInterval = 1,
    closeIdleSessions = true, productionMode = false,
    ui = MyUI.class,
    widgetset = "com.myorg.vaadin.widgetset.CombiningWidgetSet")
public final class CzrmisVaadinServlet extends VaadinServlet implements SessionInitListener
...
}

AtmospherInterceptor

public class JpaUtilAtmosphereInterceptor implements AtmosphereInterceptor {
private Logger logger = Logger.getLogger(JpaUtilAtmosphereInterceptor.class);
private final ServerExecutionTimer serverExecutionTimer;

public JpaUtilAtmosphereInterceptor() { }

@Override
public void configure(AtmosphereConfig config) { }

@Override
public Action inspect(AtmosphereResource atmosphereResource) {
  if (Util.getUser() == null) {
    VaadinSession session = (VaadinSession) atmosphereResource.getRequest().getSession().getAttribute("com.vaadin.server.VaadinSession.mysession");
    if (session != null) {
       final User user = (User) session.getAttribute(USER);
       if (user != null) {
         Util.setUser(user.getLoginName());
       }
    }
  }
  return Action.CONTINUE;
}

@Override
public void postInspect(AtmosphereResource atmosphereResource) {
  Util.close();
 }
}

UI class

@PreserveOnRefresh
@Push
@Theme(MyTheme.THEME_NAME)
public final class MyUI extends UI {
... all sorts of things going on here
}

Thanks for any help

Finally, I'm using
com.vaadin:vaadin-server:7.6.4 and the same version for the client, compler, ...etc
com.vaadin:vaadin-push:7.6.4
tomcat 7 and 8 have the same problem