Just tried 0.9.10 with slf4j 1.5.5 and I get the following exception, reverting to 0.9.9 + slf4j 1.5.5 it works fine. Not quite sure what's happening here but if there's any extra info I can provide... Caused by: java.lang.NullPointerException at java.util.HashMap.<init>(HashMap.java:223) at org ..slf4j ..impl ..CopyOnInheritThreadLocal.childValue(CopyOnInheritThreadLocal.java:20) at org ..slf4j ..impl ..CopyOnInheritThreadLocal.childValue(CopyOnInheritThreadLocal.java:11) at java.lang.ThreadLocal$ThreadLocalMap.<init>(ThreadLocal.java:334) at java.lang.ThreadLocal$ThreadLocalMap.<init>(ThreadLocal.java:242) at java.lang.ThreadLocal.createInheritedMap(ThreadLocal.java:217) at java.lang.Thread.init(Thread.java:358) at java.lang.Thread.<init>(Thread.java:419) at net.sf.ehcache.distribution.MulticastKeepaliveHeartbeatReceiver $ MulticastReceiverThread ..<init>(MulticastKeepaliveHeartbeatReceiver.java:103) at net ..sf ..ehcache ..distribution ..MulticastKeepaliveHeartbeatReceiver ..init(MulticastKeepaliveHeartbeatReceiver.java:79) at net ..sf ..ehcache ..distribution ..MulticastRMICacheManagerPeerProvider ..init(MulticastRMICacheManagerPeerProvider.java:89) at net.sf.ehcache.CacheManager.init(CacheManager.java:228) at net.sf.ehcache.CacheManager.<init>(CacheManager.java:212) at net.sf.ehcache.CacheManager.create(CacheManager.java:381) at net ..sf ..ehcache ..hibernate ..SingletonEhCacheProvider.start(SingletonEhCacheProvider.java:123) at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java: 183) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java: 1300) at org ..hibernate ..cfg ..AnnotationConfiguration ..buildSessionFactory(AnnotationConfiguration.java:859) at org ..hibernate ..ejb ..Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:669) at org ..hibernate ..ejb ..HibernatePersistence ..createContainerEntityManagerFactory(HibernatePersistence.java:132) at org ..springframework ..orm ..jpa ..LocalContainerEntityManagerFactoryBean ..createNativeEntityManagerFactory (LocalContainerEntityManagerFactoryBean.java:224) at org ..springframework ..orm ..jpa ..AbstractEntityManagerFactoryBean ..afterPropertiesSet(AbstractEntityManagerFactoryBean.java:291) at org ..springframework ..beans ..factory ..support ..AbstractAutowireCapableBeanFactory ..invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1369) at org ..springframework ..beans ..factory ..support ..AbstractAutowireCapableBeanFactory ..initializeBean(AbstractAutowireCapableBeanFactory.java:1335) ... 64 more