求助斑竹

我用的是jivejdon，我在win2000是可以的(mysql4.0.5,tomcat4.0.5)，但我将其迁移到linux时怎么也不行(tomcat4.1.24,mysql3.23),报异常如下:
java.lang.NullPointerException
at org.apache.jsp.bbs_jsp._jspService(bbs_jsp.java:525)
at org.apache.jasper.runtime.HttpJspBase.service(Unknown Source)
at javax.servlet.http.HttpServlet.service(HttpServlet.java)
at org.apache.jasper.servlet.JspServletWrapper.service(Unknown Source)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(Unknown Source)
at org.apache.jasper.servlet.JspServlet.service(Unknown Source)
at javax.servlet.http.HttpServlet.service(HttpServlet.java)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at org.apache.catalina.core.StandardWrapperValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardContextValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardContext.invoke(Unknown Source)
at org.apache.catalina.core.StandardHostValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.valves.ErrorReportValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.valves.AccessLogValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardEngineValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.connector.warp.WarpRequestHandler.handle(Unknown Source)
at org.apache.catalina.connector.warp.WarpConnection.run(Unknown Source)
at java.lang.Thread.run(Thread.java:536)

望大侠指点，或者直接到www.4o.cn上看"车友论坛"部分，谢谢！