Why not switch to 4.4 version, it's going to be out within days.
If you don't want to do it then you shall do as follows:
- grab 4.3 version from svn
- build it to make sure it works (for details go to http://community.jboss.org/wiki/jbpm4buildingfromsource)
- apply patch (jbpm-2703-extended.patch) from jira issue https://jira.jboss.org/browse/JBPM-2703
- build it once again as distro
That's it.