This was discussed in jbosscache-dev mailing list but I have moved it here. In 2.0, PojoCache has used JBoss AOP framework to obtain interceptor based architecture. As a result, it will need to do byte code weaving for some implementation classes (currently there is only one class). However, this poses a problem since the weaved code is version dependent on JBoss AOP. That is, code weaved in 1.5 can't be run in 2.0. So now AS5.0 will use 2.0 while 4.2 will stay in 1.5. What is our option? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3986543#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...