Stupid things happens... I miss add this subclass to the hibernate configuration
<bean id="sessionFactory"
name="sessionFactoriBla"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="annotatedClasses">
<list>
.......
<value>com.domain.WidgetContainer</value>
......
</list>
</property>
...
sorry