Comment # 6 on bug 1110426 from Stefan Schubert

Thanks, now it is clear.
You should cleanup your configuration file at first :-)

  <scripts>
    <init-scripts config:type="list">
      <script>
        <debug config:type="boolean">true</debug>
        <filename>zzz_reboot</filename>
        <location><![CDATA[]]></location>
        <source><![CDATA[shutdown -r now]]></source>
      </script>
      <script>
        <debug config:type="boolean">true</debug>
        <filename>zzz_halt</filename>
        <location><![CDATA[]]></location>
        <source><![CDATA[shutdown -h now]]></source>
      </script>
      <script>
        <debug config:type="boolean">true</debug>
        <filename>zzz_halt</filename>
        <location><![CDATA[]]></location>
        <source><![CDATA[shutdown -h now]]></source>
      </script>
    </init-scripts>

and zzz_halt will be called before zzz_reboot