I'm currently deploying multiple web applications (WAR's) to a JBoss 4.0.5 AS.

Each web application contains the necessary Cache & PojoCache resources, and it works as expected until I attempt to share cached data between them. For example in web application A I'm able to attach and find objects added from application A through the PojoCache api, however if I attempt to find these object in web application B I receive the following:

java.lang.ExceptionInInitializerError
 at org.jboss.cache.pojo.impl.CachedType.analyzeFields(CachedType.java:215)
...
Caused by: org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException)
 at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:538)
 at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235)
 at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:209)
 at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:353)
 at org.jboss.cache.pojo.memory.PersistentReference.<clinit>(PersistentReference.java:44)
 ... 42 more

Caused by: java.lang.NullPointerException
 at org.apache.commons.logging.impl.Log4jProxy$1.run(Log4jProxy.java:66)
 at java.security.AccessController.doPrivileged(Native Method)
 at org.apache.commons.logging.impl.Log4jProxy.threadContextClassLoader(Log4jProxy.java:88)
 at org.apache.commons.logging.impl.Log4jProxy.<init>(Log4jProxy.java:94)

 at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:39)
 at sun.reflect.GeneratedConstructorAccessor24.newInstance(Unknown Source)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
 at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
 at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529)
 ... 46 more

The web applications both use their own log4j.xml files (http://wiki.jboss.org/wiki/Wiki.jsp?page=Log4jRepositorySelector).
I have also tested the applications w/out their own logging and get the same exception.

I'm currently using the following cache configuration:

<server>
 <mbean code="org.jboss.cache.pojo.jmx.PojoCacheJmxWrapper"
 name="jboss.cache:service=PojoCache">
 <depends>jboss:service=Naming</depends>
 <depends>jboss:service=TransactionManager</depends>
 <!--
 Configure the TransactionManager
 <attribute name="TransactionManagerLookupClass">org.jboss.cache.transaction.DummyTransactionManagerLookup</attribute>
 -->
 <attribute name="TransactionManagerLookupClass">org.jboss.cache.transaction.JBossTransactionManagerLookup</attribute>
 <!--
 Isolation level : SERIALIZABLE
 REPEATABLE_READ (default)
 READ_COMMITTED
 READ_UNCOMMITTED
 NONE
 -->
 <attribute name="IsolationLevel">REPEATABLE_READ</attribute>
 <!--
 Valid modes are LOCAL
 REPL_ASYNC
 REPL_SYNC
 INVALIDATION_ASYNC
 INVALIDATION_SYNC
 -->
 <attribute name="CacheMode">REPL_SYNC</attribute>
 <!--
 Just used for async repl: use a replication queue
 -->
 <attribute name="UseReplQueue">false</attribute>
 <!--
 Replication interval for replication queue (in ms)
 -->
 <attribute name="ReplQueueInterval">0</attribute>
 <!--
 Max number of elements which trigger replication
 -->
 <attribute name="ReplQueueMaxElements">0</attribute>
 <!-- Name of cluster. Needs to be the same for all TreeCache nodes in a
 cluster in order to find each other. Note application sets this value at
 startup.
 -->
 <attribute name="ClusterName">JBossCache-Cluster-1</attribute>
 <!--Uncomment next three statements to enable JGroups multiplexer.
 This configuration is dependent on the JGroups multiplexer being
 registered in an MBean server such as JBossAS. -->
 <!--
 <depends>jgroups.mux:name=Multiplexer</depends>
 <attribute name="MultiplexerService">jgroups.mux:name=Multiplexer</attribute>
 <attribute name="MultiplexerStack">fc-fast-minimalthreads</attribute>
 -->
 <!-- JGroups protocol stack properties.
 ClusterConfig isn't used if the multiplexer is enabled and successfully initialized.
 -->
 <attribute name="ClusterConfig">
 <config>
 <UDP bind_addr="127.0.0.1"
 mcast_addr="228.10.10.10"
 mcast_port="45588"
 tos="8"
 ucast_recv_buf_size="20000000"
 ucast_send_buf_size="640000"
 mcast_recv_buf_size="25000000"
 mcast_send_buf_size="640000"
 loopback="false"
 discard_incompatible_packets="true"
 max_bundle_size="64000"
 max_bundle_timeout="30"
 use_incoming_packet_handler="true"
 ip_ttl="2"
 enable_bundling="false"
 enable_diagnostics="true"
 use_concurrent_stack="true"
 thread_naming_pattern="pl"
 thread_pool.enabled="true"
 thread_pool.min_threads="1"
 thread_pool.max_threads="25"
 thread_pool.keep_alive_time="30000"
 thread_pool.queue_enabled="true"
 thread_pool.queue_max_size="10"
 thread_pool.rejection_policy="Run"
 oob_thread_pool.enabled="true"
 oob_thread_pool.min_threads="1"
 oob_thread_pool.max_threads="4"
 oob_thread_pool.keep_alive_time="10000"
 oob_thread_pool.queue_enabled="true"
 oob_thread_pool.queue_max_size="10"
 oob_thread_pool.rejection_policy="Run"/>
 <PING timeout="2000" num_initial_members="3"/>
 <MERGE2 max_interval="30000" min_interval="10000"/>
 <FD_SOCK/>
 <FD timeout="10000" max_tries="5" shun="true"/>
 <VERIFY_SUSPECT timeout="1500"/>
 <pbcast.NAKACK max_xmit_size="60000"
 use_mcast_xmit="false" gc_lag="0"
 retransmit_timeout="300,600,1200,2400,4800"
 discard_delivered_msgs="true"/>
 <UNICAST timeout="300,600,1200,2400,3600"/>
 <pbcast.STABLE stability_delay="1000" desired_avg_gossip="50000"
 max_bytes="400000"/>
 <pbcast.GMS print_local_addr="true" join_timeout="5000"
 join_retry_timeout="2000" shun="false"
 view_bundling="true" view_ack_collection_timeout="5000"/>
 <FRAG2 frag_size="60000"/>
 <pbcast.STREAMING_STATE_TRANSFER use_reading_thread="true"/>
 <!-- <pbcast.STATE_TRANSFER/> -->
 <pbcast.FLUSH timeout="0"/>
 </config>
 </attribute>
 <!--
 Whether or not to fetch state on joining a cluster
 NOTE this used to be called FetchStateOnStartup and has been renamed to be more descriptive.
 -->
 <attribute name="FetchInMemoryState">true</attribute>
 <!--
 The max amount of time (in milliseconds) we wait until the
 state (ie. the contents of the cache) are retrieved from
 existing members in a clustered environment
 -->
 <attribute name="StateRetrievalTimeout">15000</attribute>
 <!--
 Number of milliseconds to wait until all responses for a
 synchronous call have been received.
 -->
 <attribute name="SyncReplTimeout">15000</attribute>
 <!-- Max number of milliseconds to wait for a lock acquisition -->
 <attribute name="LockAcquisitionTimeout">10000</attribute>
 <!--
 Indicate whether to use region based marshalling or not. Set this to true if you are running under a scoped
 class loader, e.g., inside an application server. Default is "false".
 -->
 <attribute name="UseRegionBasedMarshalling">true</attribute>
 </mbean>
</server>

Any hints or pointers would be appreciated.
Thanks