MBean's CacheManager attribute ClusterSize does not reflect the cluster topology when no cache is looked up

EmbeddedCacheManager manager = createCustomCacheManager( "default-config.xml", new Properties() );
		manager.start();
		MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
		final String defaultDomain = mbs.getDefaultDomain();
		ObjectName name = new ObjectName( "org.infinispan:type=CacheManager,name=\"HibernateOGM\",component=CacheManager" );

		//uncomment to "fix" the bug and gat the right cluster size
		//final Cache<Object,Object> instances = manager.getCache( "INSTANCES" );

		for (;;) {
			Thread.sleep( 5000 );
			System.out.print( "\nCluster size: " + mbs.getAttribute( name, "ClusterSize" ) );
		}