Which version of JBossASA are you using (as far as I know, there was never an EJB3 that went with 4.0.3)? Also, what version of EJB3 did you install? Also, looking at the code, I don't see how the JDBC JAR file could be affecting this (though, considering interdependencies, anything is possible). The code that blows up looks like it is scanning the EJB classes in an EJB jar file looking for annotations. Do this. Add the option "-verbose:class" to the JAVA_OPTS and run it again. This causes the JVM to print out the location of every class file loaded. Redirect stdout to a file because you will get a lot of output. Start by posting the last 20 or so class files loaded before this error occurs. Also, just to be sure, replace the older version of the JDBC JAR file and see if things still run. Finally, do a 'jar -tf jdbc.jar', where jdbc.jar is the name of the JDBC JAR file, and post the names of all classes that are not from IBM. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4111778#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...