JBoss automatically undeploys EJBs

we have a situation at office. JBoss automatically unloads all deployed EJB's without us knowing why.

here's the log we got :

2009-11-09 15:59:51,375 INFO  [org.jboss.system.server.Server] JBoss (MX MicroKernel)      [4.2.1.GA (build: SVNTag=JBoss_4_2_1_GA date=200707131605)] Started in 14s:704ms

2009-11-09 15:59:51,390 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] Periodic     recovery - first pass 
2009-11-09 15:59:51,406 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] StatusModule:     first pass 
2009-11-09 15:59:51,406 DEBUG [com.arjuna.ats.txoj.logging.txojLoggerI18N]     [com.arjuna.ats.internal.txoj.recovery.TORecoveryModule_3] - TORecoveryModule - first pass
2009-11-09 15:59:51,406 DEBUG [com.arjuna.ats.jta.logging.loggerI18N]     [com.arjuna.ats.internal.jta.recovery.info.firstpass] Local XARecoveryModule - first pass
2009-11-09 16:00:01,406 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] Periodic     recovery - second pass 
2009-11-09 16:00:01,406 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger]     AtomicActionRecoveryModule: Second pass 
2009-11-09 16:00:01,406 DEBUG [com.arjuna.ats.txoj.logging.txojLoggerI18N]     [com.arjuna.ats.internal.txoj.recovery.TORecoveryModule_6] - TORecoveryModule - second pass
2009-11-09 16:00:01,406 DEBUG [com.arjuna.ats.jta.logging.loggerI18N]     [com.arjuna.ats.internal.jta.recovery.info.secondpass] Local XARecoveryModule - second pass


2009-11-09 16:00:42,796 DEBUG [org.jboss.system.ServiceController] destroying service:     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,796 DEBUG [org.jboss.system.ServiceController] Destroy requested     before stop, calling stop now for service:     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,796 DEBUG [org.jboss.system.ServiceController] stopping service:     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,796 DEBUG [org.jboss.system.ServiceController] stopping dependent         services for:     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh dependent     services are: [ObjectName:     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestEvaluation,service=EJB3
      State: RUNNING
      I Depend On:
        persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
    , ObjectName:     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestionUtilisateur,service=E    JB3
       State: RUNNING
      I Depend On:
        persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
    ]
2009-11-09 16:00:42,796 DEBUG [org.jboss.system.ServiceController] stopping service:     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestEvaluation,service=EJB3
2009-11-09 16:00:42,796 DEBUG [org.jboss.system.ServiceController] stopping dependent     services for:     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestEvaluation,service=EJB3     dependent services are: []
2009-11-09 16:00:42,796 DEBUG [org.jboss.ejb3.stateless.StatelessDelegateWrapper]     Stopping     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestEvaluation,service=EJB3
2009-11-09 16:00:42,796 DEBUG [org.jboss.ejb.txtimer.EJBTimerServiceImpl]     removeTimerService: org.jboss.ejb.txtimer.TimerServiceImpl@134329b
2009-11-09 16:00:42,812 INFO  [org.jboss.ejb3.EJBContainer] STOPPED EJB:      com.afrikbrain.grh.ejb.session.GestEvaluation ejbName: GestEvaluation
2009-11-09 16:00:42,812 DEBUG [org.jboss.ejb3.stateless.StatelessDelegateWrapper]     Stopped     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestEvaluation,service=EJB3
2009-11-09 16:00:42,812 DEBUG [org.jboss.system.ServiceController] stopping service:     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestionUtilisateur,service=E    JB3
2009-11-09 16:00:42,812 DEBUG [org.jboss.system.ServiceController] stopping dependent     services for:     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestionUtilisateur,service=E    JB3 dependent services are: []
2009-11-09 16:00:42,812 DEBUG [org.jboss.ejb3.stateless.StatelessDelegateWrapper]     Stopping     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestionUtilisateur,service=E     JB3
2009-11-09 16:00:42,812 DEBUG [org.jboss.ejb.txtimer.EJBTimerServiceImpl]     removeTimerService: or开发者_C百科g.jboss.ejb.txtimer.TimerServiceImpl@1da817b
2009-11-09 16:00:42,812 INFO  [org.jboss.ejb3.EJBContainer] STOPPED EJB:     com.afrikbrain.grh.ejb.session.GestionUtilisateur ejbName: GestionUtilisateur
2009-11-09 16:00:42,812 DEBUG [org.jboss.ejb3.stateless.StatelessDelegateWrapper]     Stopped     jboss.j2ee:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,name=GestionUtilisateur,service=E    JB3
2009-11-09 16:00:42,812 DEBUG [org.jboss.ejb3.ServiceDelegateWrapper] Stopping     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,812 INFO  [org.jboss.ejb3.entity.PersistenceUnitDeployment]     Stopping persistence unit     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,812 INFO  [org.hibernate.impl.SessionFactoryImpl] closing
2009-11-09 16:00:42,812 INFO  [org.hibernate.impl.SessionFactoryObjectFactory]     Unbinding factory from JNDI name:     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,812 INFO  [org.hibernate.util.NamingHelper] JNDI InitialContext     properties:  {java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory,   java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces}
2009-11-09 16:00:42,812 INFO  [org.hibernate.impl.SessionFactoryObjectFactory] Unbound     factory from JNDI name:     persistence.units:ear=prjGRHProcess.ear,jar=prjGRHProcessEJB.jar,unitName=grh
2009-11-09 16:00:42,812 INFO  [org.hibernate.tool.hbm2ddl.SchemaExport] Running  hbm2ddl schema export
2009-11-09 16:00:42,812 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] import file   not found: /import.sql
2009-11-09 16:00:42,812 INFO  [org.hibernate.tool.hbm2ddl.SchemaExport] exporting     generated schema to database
2009-11-09 16:00:42,812 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table      TBA_ACT_TRANSMISSION cascade constraints
2009-11-09 16:00:42,828 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table     TBA_DEST_TRANSMISSION cascade constraints
2009-11-09 16:00:42,843 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table     TBA_DOMAINE_PROFIL cascade constraints
2009-11-09 16:00:42,859 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table     TBA_EMPLOYE_UM cascade constraints
2009-11-09 16:00:42,875 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table TBA_MANAGERS_UM cascade constraints
2009-11-09 16:00:42,890 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table TB_ACTION cascade constraints
2009-11-09 16:00:42,906 DEBUG [org.hibernate.tool.hbm2ddl.SchemaExport] drop table TB_DMDDEROGATION cascade constraints 

Set the logging level to TRACE maybe can help.

BTW, I see a similar problem with ejbs compiled with jdk1.4, deployed in a jboss running in jdk1.5. Please check the jdk versions.