When an EJB in ejbCreate throws an Exception different from CreateException, the stacktrace doesn't get printed in the log because in class org.jboss.ejb.plugins.AbstractInstancePool the exception thrown isn't wrapped in the EJBException (ex == null):

(line 174)
// Wrap e in an Exception if needed
Exception ex = null;
if( (e instanceof Exception) == false )

{ ex = new UndeclaredThrowableException(e); }

throw new EJBException("Could not instantiate bean", ex);

The solution is very simple:

@@ -176,6 +176,8 @@
if( (e instanceof Exception) == false )

{ ex = new UndeclaredThrowableException(e); + }

else

{ + ex = (Exception)e; }

throw new EJBException("Could not instantiate bean", ex);
}