This is my server.log in \jboss-as-7.0.2.Final\standalone\log, can you acquire some info from it??
When I install jbpm5 to work on mysql database, I modify hibernate.cfg.xml, persistence.xml, testDS1-ds.xml, and persistence.xml in jbpm-installer\task-service\resources\META-INF
also standalone.xml in jbpm-installer, move mysql-connector-java-5.1.18-bin.jar into jbpm-installer\db\driver.
jbpm version:5.2
mysql version:5.1.51