There has been a considerable change in Spring integration with jbpm 4.3 compared to 4.2. And not all for the better in my opinion.
I wrote a short blog about integrating Spring and jbpm 4.3. Maybe this can help you. It uses Spring 3 and it's auto configuration options so integrating jbpm with Spring is just adding 1 line to your Spring context.
blogport: http://diversit.eu/2010/01/10/jbpm-4-3-with-spring/
Cheers,
Joost