AtmosphereFramework Vaadin Push

Hi guys,
I switched from Vaadin < 7.3 to 7.5.4 and vaadin-spring. If I start my environment in eclipse, everything is fine. 
If I deploy to the server with tomcat I get an exception: 

Exception sending context initialized event to listener instance of class com.vaadin.server.communication.JSR356WebsocketInitializerjava.lang.NoSuchMethodError: com.vaadin.server.communication.PushRequestHandler.initAtmosphere(Ljavax/servlet/ServletConfig;)Lorg/atmosphere/cpr/AtmosphereFramework;
        at com.vaadin.server.communication.JSR356WebsocketInitializer.initAtmosphereForVaadinServlet(JSR356WebsocketInitializer.java:152)
        at com.vaadin.server.communication.JSR356WebsocketInitializer.contextInitialized(JSR356WebsocketInitializer.java:118)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4973)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
        at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1073)
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:553)
        at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1648)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

I am not sure, why this error happens. Maybe because I do not defined the servlet correctly?

regards,
Peter

Looks like classpath problems. com.vaadin.server.communication.PushRequestHandler#initAtmosphere method appeared in 7.5.0, probably you have old copy of vaadin-server-???.jar somewhere in your project or even in web-server libraries. Please check WEB-INF/lib folder inside your .war file, also in case of Tomcat-based web-server clean up(just delete) /work folder inside your tomcat home, and redeploy again.

Thx, I will take a look.