jBPM Version: 3.1
Application Server: JBoss 4.0.3SP1
Java Version: 1.5.0_05
Database: PostgreSQL 8.0.7

I've finally stabilized our application with jBPM but I'm encountering an error when I try to start a new process instance. Here is the stack trace:

org.hibernate.PropertyAccessException: could not set a field value by reflection setter of org.jbpm.graph.node.StartState.isAsync
 at org.hibernate.property.DirectPropertyAccessor$DirectSetter.set(DirectPropertyAccessor.java:82)
 at org.hibernate.tuple.AbstractEntityTuplizer.setPropertyValues(AbstractEntityTuplizer.java:330)
 at org.hibernate.tuple.PojoEntityTuplizer.setPropertyValues(PojoEntityTuplizer.java:188)
 at org.hibernate.persister.entity.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:3231)
 at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:126)
 at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:842)
 at org.hibernate.loader.Loader.doQuery(Loader.java:717)
 at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:223)
 at org.hibernate.loader.Loader.loadEntity(Loader.java:1782)
 at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:93)
 at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:81)
 at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:2729)
 at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:365)
 at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:346)
 at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:123)
 at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:82)
 at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:809)
 at org.hibernate.impl.SessionImpl.immediateLoad(SessionImpl.java:771)
 at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:62)
 at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:98)
 at org.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:133)
 at org.jbpm.graph.node.StartState$$EnhancerByCGLIB$$2d488654.getName(<generated>)
 at org.apache.jsp.admin.instances_jsp._jspService(org.apache.jsp.admin.instances_jsp:266)
 at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
 at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
 at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
 at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
 at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:39)
 at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:159)
 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
 at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:59)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
 at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
 at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
 at java.lang.Thread.run(Thread.java:595)
Caused by: java.lang.IllegalArgumentException
 at sun.reflect.UnsafeBooleanFieldAccessorImpl.set(UnsafeBooleanFieldAccessorImpl.java:62)
 at java.lang.reflect.Field.set(Field.java:656)
 at org.hibernate.property.DirectPropertyAccessor$DirectSetter.set(DirectPropertyAccessor.java:79)
 ... 48 more

I think it might have something to do with the fact that the Node.isAsync field is a boolean and the JBPM_NODE.ISASYNC_ column in the database is of type NUMBER(1) (rather than BIT). I noticed that the mapping in the Node.hbm.xml file did not specify a type. I dug through the Hibernate source code a little to try to find out exactly what was going on but I got lost.

I also tried setting the hibernate.query.substitutions to "true 1, false 0" but that did not seem to have any effect.

Has anyone else noticed similar behavior? Any tips for getting jBPM 3.1 running on PostgreSQL or Oracle?