Not sure if you solved this or not, or if this will help, but here is how we have our Datasource defined with Spring and JBoss:

applicationContext-hibernate.xml
Code:
	<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
		<property name="jndiName"><value>java&#58;/ProcessPointeDS</value></property>
	</bean>
web.xml:
Code:
     <resource-ref>
        <description>DB Connection</description>
        <res-ref-name>jdbc/processpointe</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
    </resource-ref>
jboss-web.xml:
Code:
<jboss-web>
	<resource-ref>
		<res-ref-name>jdbc/processpointe</res-ref-name>
		<res-type>javax.sql.DataSource</res-type>
		<jndi-name>java&#58;/ProcessPointeDS</jndi-name>
	</resource-ref>
</jboss-web>
HTH.

Regards,
Todd