I would like to kindly ask the workings of Stripes Framework together with EJB 3.0?
Stripes works very well with other frameworks, including EJB 3.0. In short, Stripes does not get in your way of integrating your favorite frameworks for completing the stack.
More specifically, Stripes has a JPA plugin, Stripersist (available at http://www.stripes-stuff.org) which makes it a breeze to use JPA/EJB 3.0 with Stripes. You can use Hibernate, JPOX, OpenJPA....since JPA is a specification, it is implementation-agnostic.