Hi,
Even i was facing same problem
with one of my applications
I had made 2 mistakes
1. listerner should be configured even
before the element
servlet. Please
refer the web.xml dtd for exact
order of various elements in web.xml
2.Since listeners are introduced in
servlet spec v 2.3, if your web.xml
is pointing to older dtds it will create
problem
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_3.dtd">
if its '2.2' instead of '2.3' it will not work
Hope this helps