tomcat问题,经常挂死！！

jdk:1.4.2_05
tomcat:tomcat-4.1.18
log包：log4j-1.2.8.jartomcat运行一段时间就会自动挂死，导致系统无法登陆！！org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: Class org.apache.commons.logging.impl.Log4JCategoryLog does not implement Log
        at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:555)
        at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:289)
        at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:409)
        at org.apache.tomcat.util.log.CommonLogHandler.log(CommonLogHandler.java:97)
        at org.apache.tomcat.util.log.Log.log(Log.java:198)
        at org.apache.tomcat.util.log.Log.log(Log.java:192)
        at org.apache.tomcat.util.log.Log.log(Log.java:174)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:533)
        at java.lang.Thread.run(Thread.java:534)
Caused by: org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: Class org.apache.commons.logging.impl.Log4JCategoryLog does not implement Log
        at org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:420)
        at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:548)
        ... 8 more
Caused by: org.apache.commons.logging.LogConfigurationException: Class org.apache.commons.logging.impl.Log4JCategoryLog does not implement Log
        at org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:416)
        ... 9 more