How do I allow directory listing for specific web applications in JBoss 5.1.0?

Hi Experts

I have two applications deployed on a JBoss 5.1.0.
The primary application is deployed in jboss/server/default/deploy/advisor.war and it shouldn't have directory listings enabled, which isn't an issue as JBoss disables dir listings per default.
The secondary application is deployed (exploded) in an external folder and is used only for serving images, documents and animations to the primary application.

I need to have directory listings enabled for the second application as a search engine needs to crawl the folders looking for files to add to its index.

Directory listings can be enabled/disabled globally in server/default/deployers/jbossweb.deployer/web.xml using the "listings" init-param but I need to be able to override that for only one application.

I've tried putting the "default" servlet definition found in server/default/deployers/jbossweb.deployer/web.xml into the war files web.xml but JBoss tells me that it cannot add the servlet as a servlet with the name default already exists.
Changing the name of the default servlet in the applications web.xml yields no result.

Anyone know how to do this?

Thanks!

Regards
/Lars