jboss升级报错

项目原来运行在jboss3.2.3上，之后系统升级，使用jdk1.6重新编译打包，部署在jboss4上（jboss4.0.5），系统使用oracle数据库，版本是9i，数据库驱动也由原来的ojdbc14换成了ojdbc6，现在出现的问题是，访问需要读取数据库数据的页面，第一次总会报错（但是不影响数据库的连接，可以连接并查询数据），不知该如何处理，请各位不吝赐教，具体的错误信息如下：2013-02-04 15:29:18,546 ERROR [STDERR] 2013-2-4 15:29:18 oracle.jdbc.driver.OracleDriver registerMBeans
: Error while registering Oracle JDBC Diagnosability MBean.
java.lang.Error: Loader repository is not an instance of LoaderRepository: org.jboss.mx.loading.UnifiedLoaderRepository3
at org.jboss.mx.server.MBeanServerImpl.getClassLoaderRepository(MBeanServerImpl.java:1123)
at org.jboss.mx.server.MBeanServerImpl.<init>(MBeanServerImpl.java:199)
at org.jboss.mx.server.MBeanServerBuilderImpl.newMBeanServer(MBeanServerBuilderImpl.java:71)
at javax.management.MBeanServerFactory.newMBeanServer(MBeanServerFactory.java:310)
at javax.management.MBeanServerFactory.createMBeanServer(MBeanServerFactory.java:213)
at javax.management.MBeanServerFactory.createMBeanServer(MBeanServerFactory.java:174)
at sun.management.ManagementFactory.createPlatformMBeanServer(ManagementFactory.java:302)
at java.lang.management.ManagementFactory.getPlatformMBeanServer(ManagementFactory.java:504)
at oracle.jdbc.driver.OracleDriver.registerMBeans(OracleDriver.java:302)
at oracle.jdbc.driver.OracleDriver$1.run(OracleDriver.java:199)
at java.security.AccessController.doPrivileged(Native Method)
at oracle.jdbc.driver.OracleDriver.<clinit>(OracleDriver.java:195)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at sun.misc.Service$LazyIterator.next(Service.java:271)
at java.sql.DriverService.run(DriverManager.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.sql.DriverManager.loadInitialDrivers(DriverManager.java:506)
at java.sql.DriverManager.initialize(DriverManager.java:612)
at java.sql.DriverManager.getDriver(DriverManager.java:228)
at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.isDriverLoadedForURL(LocalManagedConnectionFactory.java:300)
at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.getDriver(LocalManagedConnectionFactory.java:264)
at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:170)
at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:565)
at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:250)
at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:491)
at org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:341)
at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:301)
at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:396)
at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:842)
at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:88)
at net.sf.hibernate.connection.DatasourceConnectionProvider.getConnection(DatasourceConnectionProvider.java:59)
at net.sf.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:72)
at net.sf.hibernate.cfg.Configuration.buildSettings(Configuration.java:1119)
at net.sf.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:748)
at com.bsteel.portal2.util.HibernateUtil.getSessionFactory(HibernateUtil.java:65)
at com.bsteel.portal2.util.HibernateUtil.getSession(HibernateUtil.java:39)
附HibernateUtil的代码如下：package com.bsteel.portal2.util;import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.cfg.Configuration;public class HibernateUtil {
    // hibernate session factory
    private static SessionFactory factory;    /**
     * 获取一个hibernate session
     * 
     * @throws DBException
     * @return Session
     */
    public static Session getSession() throws Exception {
        Session s = null;
        try {
            getSessionFactory();
            s = factory.openSession();
        } catch (Exception e) {
            throw e;
        }
        return s;
    }    /**
     * 获取一个hibernate session factory
     * 
     * @throws Exception
     * @return SessionFactory
     */
    public static synchronized SessionFactory getSessionFactory() throws Exception {
        if (factory != null) {
            return factory;
        }
        Configuration cfg = new Configuration();
        cfg.configure("/portal2/hibernate.cfg.portal2.xml");
        factory = cfg.buildSessionFactory();
        if (factory == null) {
            throw new Exception("factory not found");
        }
        return factory;
    }
}