Solucionado!!
<bean id="transactionManager" class="org.springframework.orm.hibernate3.Hibernat eTransactionManager">
<property name="sessionFactory"><ref bean="sessionFactory"/></property>
</bean>
<bean id="alumnoTransaction" class="org.springframework.transaction.interceptor .TransactionProxyFactoryBean">
<property name="transactionManager" ref="transactionManager" />
<property name="target" ref="alumnoDaoImp" />
<property name="transactionAttributes">
<!-- define the transaction specs here -->
<props>
<prop key="save*">PROPAGATION_REQUIRED</prop>
<prop key="delete*">PROPAGATION_REQUIRED</prop>
<prop key="*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>
Saludos!!