Following my last post, this apply for jbpm-5.3.0.Final-installer-full.zip clean install. (or reinstall with "ant stop.demo"; "ant clean.demo"; "ant install.demo"). This replacement help me to following the examples in jPBM v5.3 userguide http://docs.jboss.org/jbpm/v5.3/userguide/ch.installer.html#d0e469.
In fact, I did checkout the lastest successful build (09/August/12, jbpm, form-builder, designer) and let maven run for hours. With all the latest target/{*.tar,jar,war,zip} files, but the procedured jbpm/jbpm-install come up with so many errors. (of course, we can wait for the next release (01/Oct/12 for 5.4 version) with all currens issues in the trunk fixed https://issues.jboss.org/browse/JBPM?selectedTab=com.atlassian.jira.plugin.system.project:versions-panel&subset=-1). And using human-task-war version 5.4 SNAPSHOT with jbpm-5.3.0.final did not work for me either.
I hope this helps,
-Quang