diff --git a/org.adempiere.ui.zk/WEB-INF/src/fi/jawsy/jawwa/zk/atmosphere/ZkAtmosphereHandler.java b/org.adempiere.ui.zk/WEB-INF/src/fi/jawsy/jawwa/zk/atmosphere/ZkAtmosphereHandler.java
index 049aaf509c..a3c5c3e65f 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/fi/jawsy/jawwa/zk/atmosphere/ZkAtmosphereHandler.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/fi/jawsy/jawwa/zk/atmosphere/ZkAtmosphereHandler.java
@@ -43,6 +43,7 @@ import org.zkoss.zk.ui.sys.WebAppCtrl;
  */
 public class ZkAtmosphereHandler implements AtmosphereHandler {
 
+	private static final String SESSION_NOT_FOUND = "SessionNotFound";
 	private final Logger log = LoggerFactory.getLogger(this.getClass());
 	
     @Override
@@ -111,7 +112,7 @@ public class ZkAtmosphereHandler implements AtmosphereHandler {
     	Session session = WebManager.getSession(resource.getAtmosphereConfig().getServletContext(), request, false);
     	if (session == null) {
     		log.warn("Could not find session: " + request.getRequestURI());
-    		return new Either<String, Session>("Could not find session", null);
+    		return new Either<String, Session>(SESSION_NOT_FOUND, null);
     	} else {
     		return new Either<String, Session>(null, session);
     	}
@@ -128,7 +129,7 @@ public class ZkAtmosphereHandler implements AtmosphereHandler {
         if (error != null && serverPushEither.getRightValue() == null) {
         	if (log.isDebugEnabled())
         		log.warn("Bad Request. Error="+error+", Request="+resource.getRequest().getRequestURI());
-            response.setStatus(HttpServletResponse.SC_NO_CONTENT);
+            response.setStatus(HttpServletResponse.SC_BAD_REQUEST, error);
             response.getWriter().write("");
             response.getWriter().flush();
             return;
diff --git a/org.adempiere.ui.zk/WEB-INF/src/web/js/jawwa/atmosphere/serverpush.js b/org.adempiere.ui.zk/WEB-INF/src/web/js/jawwa/atmosphere/serverpush.js
index eabe053fe0..ace93ffb81 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/web/js/jawwa/atmosphere/serverpush.js
+++ b/org.adempiere.ui.zk/WEB-INF/src/web/js/jawwa/atmosphere/serverpush.js
@@ -58,7 +58,11 @@
       this.ajaxOptions.complete = function() {
     	  if (me.trace)
     		  console.log("complete"+ " dtid: " + me.desktop.id);
-    	  me._schedule();
+    	  if (me._req && me._req.statusText == "SessionNotFound" && me._req.status == 400) {
+    		  ;//stop sent request:IDEMPIERE-4237
+    	  } else {
+    		  me._schedule();
+    	  }
       };
     },
     _schedule: function() {