Message3520

This boils down to this line failing in oracle.jdbc.driver.OracleDriver:
       Class class1 =
Class.forName("oracle.as.jmx.framework.PortableMBeanFactory");

Running jython with the "--verify" flag silences the error.  Without
that flag, jython loads itself in the system classpath, which causes
problems with dynamic class loading from elsewhere in the CLASSPATH
heirarchy.  

So this is a much bigger issue.  In this particular case, the failure is
relatively benign because Oracle continues if it isn't able to register
the driver as an MBean, but the general problem will crop up elsewhere.