Usually when you get the message indicating that "java:comp is not bound in this Context" it means that you screwed up the resource configuration. Typically you didn't put it in the web.xml

However, a more interesting scenario cropped up on the Java forums recently.

The user was running Tomcat and had copied the contents of common/lib into their app's WEB-INF/lib directory for some reason (probably paranoid about classpaths).

This includes the naming JAR and that means that the user's app saw a different JNDI environment from the rest of the App server; their app was seeing the static members of their classloaded JAR instead of the application server's one.