Yes, OKMWorkflow database must contains jbpm tables ... but you might not copy directly from hypersonic, rememeber could be some diference between hypersonic tables declaration and postgresql declarion, you must execute scripts in you empty postgresql database to create the structure needed by jbpm
I already created them... I adapted the script to PostgreSQL and successful created the 32 tables.
I don't know hoe to put that database (OKMWorkflow) to use