gwt upgrade to 2.4 problem

Hellow,
i'm trying to update to the newst gwt version 2.4
as needed i upgraded all other jars include hibernate.
unfortunately, the hibernate object now throuing error and can't create new instance

private HttpSessionManager() {
sf = new Configuration().configure().buildSessionFactory();
}

i get the following error : org.hibernate.HibernateException: Unable to get the default Bean Validation factory

this is my classpath:

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
<classpathentry kind="src" path="src"/>
<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
<classpathentry combineaccessrules="false" kind="src" path="/VibeSecCommon"/>
<classpathentry kind="lib" path="/lib/gwt/aopalliance.jar"/>
<classpathentry kind="lib" path="/lib/gwt/gin-src.jar"/>
<classpathentry kind="lib" path="/lib/gwt/gin-1.5.zip"/>
<classpathentry kind="lib" path="/lib/gwt/guice-3.0.jar"/>
<classpathentry kind="lib" path="/lib/gwt/gwt-servlet-deps.jar"/>
<classpathentry kind="lib" path="/lib/gwt/gwt-dnd-2.6.5-javadoc.jar"/>
<classpathentry kind="lib" path="/lib/gwt/gwt-dnd-2.6.5.jar"/>
<classpathentry kind="lib" path="/lib/gwt/gwt-log-2.6.2.jar"/>
<classpathentry kind="lib" path="/lib/gwt/smartgwt-skins.jar"/>
<classpathentry kind="lib" path="/lib/gwt/smartgwt.jar"/>
<classpathentry kind="lib" path="/lib/server/log4j-1.2.13.jar"/>
<classpathentry kind="lib" path="/lib/server/antlr-2.7.6.jar"/>
<classpathentry kind="lib" path="/lib/server/commons-collections-3.1.jar"/>
<classpathentry kind="lib" path="/lib/server/dom4j-1.6.1.jar"/>
<classpathentry kind="lib" path="/lib/gwt/validation-api-1.0.0.GA.jar"/>
<classpathentry kind="lib" path="/lib/server/hibernate-jpa-2.0-api-1.0.0.Final.jar"/>
<classpathentry kind="lib" path="/lib/server/hibernate3.jar"/>
<classpathentry kind="lib" path="/lib/server/javassist-3.9.0.GA.jar"/>
<classpathentry kind="lib" path="/lib/server/jta-1.1.jar"/>
<classpathentry kind="lib" path="/lib/server/slf4j-api-1.5.8.jar"/>
<classpathentry kind="lib" path="/lib/server/slf4j-jdk14-1.5.8.jar"/>
<classpathentry kind="lib" path="/lib/gwt/GWT FX v0.5.0 MS 1.jar"/>
<classpathentry kind="lib" path="/lib/server/jdom.jar"/>
<classpathentry kind="lib" path="/lib/server/commons-logging-1.1.1.jar"/>
<classpathentry kind="lib" path="/lib/gwt/javax.inject.jar"/>
<classpathentry kind="lib" path="/lib/server/postgresql-8.4-701.jdbc3.jar"/>
<classpathentry combineaccessrules="false" kind="src" path="/KPImine"/>
<classpathentry kind="lib" path="C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/gwt-user.jar">
<attributes>
<attribute name="javadoc_location" value="file:/C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/doc/javadoc/"/>
</attributes>
</classpathentry>
<classpathentry kind="lib" path="C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/gwt-dev.jar">
<attributes>
<attribute name="javadoc_location" value="file:/C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/doc/javadoc/"/>
</attributes>
</classpathentry>
<classpathentry kind="lib" path="C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/validation-api-1.0.0.GA-sources.jar"/>
<classpathentry kind="lib" path="C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/validation-api-1.0.0.GA.jar" sourcepath="C:/Dev/eclipse3.7/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.relr37v201110112027/gwt-2.4.0/validation-api-1.0.0.GA-sources.jar"/>
<classpathentry kind="output" path="war/WEB-INF/classes"/>
</classpath>

any advices ???

thanks for your help