Exception while using coherence clustering

I’m running OpenFire 3.7.1 with the latest clustering plugin from Ignite Realtime plugins page and with coherence jars of 3.3.11 build 389, I got the following exception on server startup:

2011.11.01 18:28:50 org.jivesoftware.openfire.cluster.ClusterManager - Unable to access backing cache for Routing User Sessions. BackingMapManager is a com.tangosol.net.DefaultConfigurableCacheFactory$Manager and backing map is com.tangosol.net.cache.LocalCache

java.lang.IllegalStateException: Unable to access backing cache for Routing User Sessions. BackingMapManager is a com.tangosol.net.DefaultConfigurableCacheFactory$Manager and backing map is com.tangosol.net.cache.LocalCache

at com.jivesoftware.util.cache.ClusteredCache.init(ClusteredCache.java:106)

at com.jivesoftware.util.cache.ClusteredCache.(ClusteredCache.java:59)

at com.jivesoftware.util.cache.CoherenceClusteredCacheFactory.createCache(Coherenc eClusteredCacheFactory.java:177)

at org.jivesoftware.util.cache.CacheFactory.joinedCluster(CacheFactory.java:674)

at org.jivesoftware.openfire.cluster.ClusterManager$1.run(ClusterManager.java:61)

Any Idea?

It occures both on Linux and Windows XP installed servers

Thanks,

Eitan