In jBPM 5.0 CR1 you still need to configure Drools to use jBPM5 instead of the old Drools Flow (note that this is no longer necessary in the latest jBPM5 snapshot as Drools has now also updated to jBPM5), here is how you should create your session (with JPA persistence):
Properties properties = new Properties();
properties.put("drools.processInstanceManagerFactory", "org.jbpm.persistence.processinstance.JPAProcessInstanceManagerFactory");
properties.put("drools.processSignalManagerFactory", "org.jbpm.persistence.processinstance.JPASignalManagerFactory");
KnowledgeSessionConfiguration config = KnowledgeBaseFactory.newKnowledgeSessionConfiguration(properties);
return JPAKnowledgeService.newStatefulKnowledgeSession(kbase, config, env);
In jBPM5 snapshot, you can just use what you were using.
Kris