You probably haven’t configured Weblogic to compile your JSP’s in debug mode. You can do this in the weblogic.xml file like this:
<!DOCTYPE weblogic-web-app PUBLIC "-//BEA
Systems, Inc.//DTD Web Application 7.0//EN"
"http://www.bea.com/servers/wls700/dtd/weblogic700-web-jar.dtd">
<weblogic-web-app>
<description>WebLogic Descriptor</description>
<jsp-descriptor>
<jsp-param>
<param-name>debug</param-name>
<param-value>true</param-value>
</jsp-param>
</jsp-descriptor>
</weblogic-web-app>