我在JBuilder2005 下调试简单的jsp页面时出现了这个问题

Help viewer error
URL: Unable to open location: Document not found on server

JBuilder中的信息窗口中的全部信息如下：

D:\Java\jdk1.5.0_10\bin\javaw -classpath "D:\Borland\JBuilder2005\thirdparty\jakarta-tomcat-5.0.27\bin\bootstrap.jar;D:\Java\jdk1.5.0_10\lib\tools.jar" "-Dcatalina.home=D:/Borland/JBuilder2005/thirdparty/jakarta-tomcat-5.0.27" org.apache.catalina.startup.Bootstrap -config D:\wutong\EC\Tomcat\conf\server8080.xml start
2007-5-4 22:17:10 org.apache.coyote.http11.Http11Protocol init
信息: Initializing Coyote HTTP/1.1 on http-8080
2007-5-4 22:17:10 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 1391 ms
2007-5-4 22:17:10 org.apache.catalina.core.StandardService start
信息: Starting service Catalina
2007-5-4 22:17:10 org.apache.catalina.core.StandardEngine start
信息: Starting Servlet Engine: Apache Tomcat/5.0.27
2007-5-4 22:17:10 org.apache.catalina.core.StandardHost start
信息: XML validation disabled
2007-5-4 22:17:12 org.apache.struts.util.PropertyMessageResources <init>
信息: Initializing, config='org.apache.struts.util.LocalStrings', returnNull=true
2007-5-4 22:17:12 org.apache.struts.util.PropertyMessageResources <init>
信息: Initializing, config='org.apache.struts.action.ActionResources', returnNull=true
2007-5-4 22:17:12 org.apache.struts.util.PropertyMessageResources <init>
信息: Initializing, config='ApplicationResources', returnNull=true
2007-5-4 22:17:15 org.apache.catalina.core.StandardHost getDeployer
信息: Create Host deployer for direct deployment ( non-jmx )
2007-5-4 22:17:16 org.apache.coyote.http11.Http11Protocol start
信息: Starting Coyote HTTP/1.1 on http-8080
2007-5-4 22:17:16 org.apache.catalina.startup.Catalina start
信息: Server startup in 5078 ms
StandardWrapperValve[debugjsp]: Servlet debugjsp is currently unavailable

我一直没明白红色字体那句话是什么意思？是Servlet的xml配置文件有错误吗？
劳驾有经验的朋友帮忙看看！！　３Ｑ！！

[此贴子已经被作者于2007-5-4 22:34:16编辑过]