On Websphere 6.1, the class-loader hierarchy and our security policies did not allow for JAMon libs to be added at the system class-loader level.
One option was to include the contents of the JAMon war file into our WAR file.
But I thought a cleaner option would be to make a EAR file with 2 web-modules (one war of my application and other jamon.war)
On WAS 6.1, I changed the class-loader policy of the application to: Single class loader for application.
The application.xml file for the EAR file contained the following items:
<application id="Application_ID">
<display-name>MyApplication.ear</display-name>
<module>
<web>
<web-uri>MyApplication.war</web-uri>
<context-root>MyApplication</context-root>
</web>
</module>
<module>
<web>
<web-uri>jamon.war</web-uri>
<context-root>jamon</context-root>
</web>
</module>
</application>