To fix the hibernate mappings for XDoclet, a post processing ant task 
could be used like this:

       <replace dir="${build.hibernate.dir}" value="&lt;hibernate-
mapping default-lazy=&quot;false&quot; &gt;">
         <include name="**/*.hbm.xml"/>
         <replacetoken><![CDATA[<hibernate-mapping>]]></replacetoken>
       </replace>
       <replace dir="${build.hibernate.dir}" value="Hibernate Mapping 
DTD 3.0">
         <include name="**/*.hbm.xml"/>
         <replacetoken>Hibernate Mapping DTD 2.0</replacetoken>
       </replace>
       <replace dir="${build.hibernate.dir}" value="hibernate-mapping-
3.0.dtd">
         <include name="**/*.hbm.xml"/>
         <replacetoken>hibernate-mapping-2.0.dtd</replacetoken>
       </replace>

Cheer,

Rudie Ekkelenkamp.