Hi Marciej, thanks for your answer.
My project classpath contains all jars included in jBPM runtime, including the Hibernate ones. Should I add other libraries?
activation-1.1.jar
antlr-2.7.7.jar
antlr-3.3.jar
antlr-runtime-3.3.jar
antlr-runtime.jar
aopalliance-1.0.jar
asm-3.3.jar
btm-2.1.2.jar
commons-collections-3.2.1.jar
commons-compress-1.0.jar
commons-exec-1.0.1.jar
commons-io-1.4.jar
commons-logging-1.1.1.jar
commons-net-2.0.jar
commons-vfs2-2.0.jar
cxf-api-2.4.4.jar
cxf-common-utilities-2.4.4.jar
cxf-rt-bindings-soap-2.4.4.jar
cxf-rt-bindings-xml-2.4.4.jar
cxf-rt-core-2.4.4.jar
cxf-rt-databinding-jaxb-2.4.4.jar
cxf-rt-frontend-jaxws-2.4.4.jar
cxf-rt-frontend-simple-2.4.4.jar
cxf-rt-transports-common-2.4.4.jar
cxf-rt-transports-http-2.4.4.jar
cxf-rt-ws-addr-2.4.4.jar
cxf-tools-common-2.4.4.jar
dom4j-1.6.1.jar
drools-compiler-5.5.0.Final.jar
drools-compiler.jar
drools-core-5.5.0.Final.jar
drools-core.jar
drools-persistence-jpa-5.5.0.Final.jar
ecj-3.5.1.jar
ejb3-persistence-1.0.2.GA.jar
geronimo-javamail_1.4_spec-1.7.1.jar
h2-1.3.161.jar
hibernate-annotations-3.4.0.GA.jar
hibernate-commons-annotations-3.1.0.GA.jar
hibernate-core-3.3.2.GA.jar
hibernate-entitymanager-3.4.0.GA.jar
hibernate-jpa-2.0-api-1.0.1.Final.jar
hornetq-core-2.2.10.Final.jar
javassist-3.14.0-GA.jar
jaxb-impl-2.2.5.jar
jaxb-xjc-2.2.5.jar
jbpm-bam-5.4.0.Final.jar
jbpm-bam.jar
jbpm-bpmn2-5.4.0.Final.jar
jbpm-bpmn2.jar
jbpm-flow-5.4.0.Final.jar
jbpm-flow-builder-5.4.0.Final.jar
jbpm-flow-builder.jar
jbpm-flow.jar
jbpm-human-task-core-5.4.0.Final.jar
jbpm-human-task-hornetq-5.4.0.Final.jar
jbpm-human-task-jms-5.4.0.Final.jar
jbpm-human-task-mina-5.4.0.Final.jar
jbpm-persistence-jpa-5.4.0.Final.jar
jbpm-test-5.4.0.Final.jar
jbpm-workitems-5.4.0.Final.jar
jdom-1.0.jar
jsr173_1.0_api.jar
jta-1.1.jar
junit.jar
knowledge-api-5.5.0.Final.jar
knowledge-api.jar
knowledge-internal-api-5.5.0.Final.jar
knowledge-internal-api.jar
librerie.txt
log4j-1.2.16.jar
mail-1.4.jar
mina-core-2.0.1.jar
mvel2-2.1.3.Final.jar
mvel2.jar
mysql-connector-java-5.0.8-bin.jar
neethi-3.0.2.jar
netty-3.2.0.Final.jar
org.eclipse.jdt.core_3.8.2.v20120814-155456.jar
protobuf-java-2.4.1.jar
resolver.jar
rome-1.0.jar
slf4j-api-1.6.4.jar
slf4j-api.jar
slf4j-log4j12-1.6.4.jar
smack-3.0.4.jar
spring-aop-3.0.6.RELEASE.jar
spring-asm-3.0.6.RELEASE.jar
spring-beans-3.0.6.RELEASE.jar
spring-context-3.0.6.RELEASE.jar
spring-core-3.0.6.RELEASE.jar
spring-expression-3.0.6.RELEASE.jar
spring-web-3.0.6.RELEASE.jar
stax2-api-3.1.1.jar
stringtemplate-3.2.1.jar
woodstox-core-asl-4.1.1.jar
workflow-params.jar
wsdl4j-1.6.2.jar
xbean.jar
xbean_xpath.jar
xml-apis-1.3.04.jar
xml-resolver-1.2.jar
xmlbeans-qname.jar
xmlpublic.jar
xmlpull-1.1.3.1.jar
xmlschema-core-2.0.2.jar
xpp3_min-1.1.4c.jar
xpp3_min.jar
xstream-1.4.1.jar
xstream.jar