If you are testing, I had to expose the Hypersonic database via TCP in Jboss. Check the hsql-ds.xml file I believe there are comments in there regarding between the ways you can setup (TCP/IP versus the other ways - default is NOT TCP/IP).
This was for testing, if you are deploying it within Jboss I'm not sure.
Thanks, when I revised and deployed the DB tutorial to jBoss, it worked.
I haven't had any success related to persisting tasks though.