http://jira.jboss.com/jira/browse/JBPM-904
in tasks, the notify attribute and reminder element are not properly modelled in the schema. it's fixed in cvs for 3.2.1. i'll be uploading the fixed schema online right away.
the official url will be http://jbpm.org/xsd/jbpm-3.2.xsd (working on getting that published)
but in the meantime, you can find it here: http://docs.jboss.org/jbpm/xsd/jpdl-3.2.xsd
regards, tom.