In the log I'm not seeing hibernate trying to create SessionInfo or any of the non-task related tables. So, again, are you 100% sure you are using persistence unit 'org.jbpm.persistence.jpa' in you application? Are you (or spring, or whatever framework you may be using) creating an EntityManagerFactory based on that specific persistence unit?
And, one more time, are you 100% sure about the fact of using the same data-source for the 2 persistence units you have?
Best Regards,