Using Spring AOP with CGLIB and Spring Data Neo4j - problem with repositories

Hi guys,
I'm writing a sample web application with two sources of data: a standard RDBMS (Postgres), integrated through MyBatis, and a Neo4j graph db.
To support transactions (only on the RDBMS side, I don't want to mix data retrieving) I enabled AOP transaction management (with tx:advice and aop:config pointcuts) with proxy-target-class="true" (CGLIB proxy implementation), as my service layer beans are implemented without interfaces.

One of my service bean is injected with a repository bean (@Autowired), that is enabled with the following xml configuration:
<neo4j:repositories base-package="com.mypackage.graph.repository"/>

The signature of the repository bean is "public interface FormRepository extends GraphRepository<Form>".

When I enable AOP config with CGLIB proxy, i receive the following error on the service bean:
java.lang.IllegalArgumentException: Cannot subclass final class class com.sun.proxy.$Proxy75

In fact, the CGLIB library doesn't manage to create the proxy of the service bean because there is an autowired field implemented by an interface, isn't it?

There is a way to make it work with CGLIB configuration?

Thanks
Marco