请问Jboss-6.0.0-Final在启动时出现下面这个WARN提示是因为什么原因引起的？
13:56:38,031 INFO [jbossatx] ARJUNA-32010 JBossTS Recovery Service (tag: JBOSSTS_4_14_0_Final) - JBoss Inc.
13:56:38,037 INFO [arjuna] ARJUNA-12324 Start RecoveryActivators
13:56:38,055 INFO [arjuna] ARJUNA-12296 ExpiredEntryMonitor running at 星期一, 26 九月 2011 13:56:38
13:56:38,132 INFO [arjuna] ARJUNA-12310 Recovery manager listening on endpoint 127.0.0.1:4712
13:56:38,133 INFO [arjuna] ARJUNA-12344 RecoveryManagerImple is ready on port 4712
13:56:38,133 INFO [jbossatx] ARJUNA-32013 Starting transaction recovery manager
13:56:38,153 INFO [arjuna] ARJUNA-12163 Starting service com.arjuna.ats.arjuna.recovery.ActionStatusService on port 4713
13:56:38,155 INFO [arjuna] ARJUNA-12337 TransactionStatusManagerItem host: 127.0.0.1 port: 4713
13:56:38,278 INFO [arjuna] ARJUNA-12170 TransactionStatusManager started on port 4713 and host 127.0.0.1 with service com.arjuna.ats.arjuna.recovery.ActionStatusService
13:56:38,319 INFO [jbossatx] ARJUNA-32017 JBossTS Transaction Service (JTA version - tag: JBOSSTS_4_14_0_Final) - JBoss Inc.
13:56:38,363 INFO [arjuna] ARJUNA-12202 registering bean jboss.jta:type=ObjectStore.
13:56:38,617 WARN [arjuna] ARJUNA-12148 Other Exception: java.lang.NullPointerException
at com.arjuna.ats.arjuna.recovery.ActionStatusService.doWork(ActionStatusService.java:111) [:6.0.0.Final]
at com.arjuna.ats.internal.arjuna.recovery.Connection.run(Connection.java:87) [:6.0.0.Final]
13:56:38,621 WARN [arjuna] ARJUNA-12148 Other Exception: java.lang.NullPointerException
at com.arjuna.ats.arjuna.recovery.ActionStatusService.doWork(ActionStatusService.java:111) [:6.0.0.Final]
at com.arjuna.ats.internal.arjuna.recovery.Connection.run(Connection.java:87) [:6.0.0.Final]
13:56:38,626 WARN [arjuna] ARJUNA-12148 Other Exception: java.lang.NullPointerException
at com.arjuna.ats.arjuna.recovery.ActionStatusService.doWork(ActionStatusService.java:111) [:6.0.0.Final]
at com.arjuna.ats.internal.arjuna.recovery.Connection.run(Connection.java:87) [:6.0.0.Final]
