SSI in TOMCAT - A bit off-topic!

Has anyone activated Server Side Include(SSI) in Tomcat 4.1 ?

I have followed the normal instruction under Apache's Tomcat website,
including :
1. Renaming servlets-ssi.renametojar to servlets-ssi.jar in directory
CATALINA_HOME/server/lib/ ;

2. Uncommented <servlet><servlet-name>ssi</servlet-name>...</servlet> and
<servlet-mapping>
        <servlet-name>ssi</servlet-name>
        <url-pattern>*.shtml</url-pattern>
    </servlet-mapping>
in web.xml in directory CATALINA_HOME/conf/ ;

3.Created a *.shtml file with the necessary <servlet code=..><param name=..
value=..></servlet> tags.

The problem is : when I call this *.shtml file under Tomcat, it does seems to
recognise my servlet - it only output its text content - although when I
directly call the servlet, it has no problem rendering its output.

Any help will be much appreciated.

Bob.

p.s.: I have googled, but can't find any solution. Sorry for the slight
off-topic once again.