When deploying jbpm.jar in a jboss environment we saw the following issue popping up.
In the hibernate mapping files a typedef is used (string_max), which is only specified in hibernate.queries.hbm.xml. Other mapping files are using this typedef (Comment, Timer,...).
This has as consequence that the hibernate.queries.hbm.xml mapping file must be read before the other, otherwise you get exceptions like:
org.hibernate.MappingException: Could not determine type for: string_max, for columns: [org.hibernate.mapping.Column(DESCRIPTION_)] at org.hibernate.mapping.SimpleValue.getType(SimpleVa lue.java:265)