Updating web.xml not being recognized...

Hi all:

We have a web app deployed in WAS 5.1. I need to add a servlet to the app. 
(This is a web facing application.) Instead of rebuilding the war file, I 
just placed the servlet class file in the WEB-INF/classes/<package name> 
folder and modified the web.xml to add the <servlet> and <servlet-mapping> 
information. However, the app never seems to recognize this new servlet. 
We get a 404 page when it is called and there is no mention of it at all 
in the SystemOut.log. I have even taken the web.xml from another system 
with the same web app and replaced the old web.xml with it. The webfaced 
app runs fine, but my new servlet is still not being found. I can tell 
this by going in to the Admin Console and looking at the deployment 
descriptor The servlet is not shown.

Any ideas what may be going on?

thanks in advance,

Mike