Extracts from the 4 pages (out of 130K text/html pages from dmoz.org a year ago) that use RDFa attributes with creativecommons.org namespaces:

http://www.invaligia.com/ uses href="www.invaligia.com", i.e. a relative URI, so it's referring to the wrong document:

    <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/2.5/it/">
    <img alt="Creative Commons License" style="border-width:0" src="http://creativecommons.org/images/public/somerights20.png" />
    </a>
    <br />
    <span xmlns:dc="http://purl.org/dc/elements/1.1/" href="http://purl.org/dc/dcmitype/InteractiveResource" property="dc:title" rel="dc:type">Cosa mettere in valigia - liste pronte per tutte le partenze</span> by 
    <a xmlns:cc="http://creativecommons.org/ns#" href="www.invaligia.com" property="cc:attributionName" rel="cc:attributionURL">www.invaligia.com</a> is licensed under a 
    <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/2.5/it/">Creative Commons Attribuzione-Non commerciale-Non opere derivate 2.5 Italia License</a>.
    <br />Based on a work at 
    <a xmlns:dc="http://purl.org/dc/elements/1.1/" href="www.invaligia.com" rel="dc:source">www.invaligia.com</a>.

http://roswila-dreamspoetry.blogspot.com/ is not well-formed XML - see the misnested <font>:

    <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/us/">
    <img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/us/88x31.png" />
    </a>
    <br />
    <span xmlns:dc="http://purl.org/dc/elements/1.1/" property="dc:title"><em><font size="1">Roswila's Dreams and Poetry Realm</span> by 
    <a xmlns:cc="http://creativecommons.org/ns#" href="http://roswila-dreamspoetry.blogspot.com" property="cc:attributionName" rel="cc:attributionURL">Patricia Kelly (a/k/a Roswila)</a> is licensed under a 
    <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/us/">Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License</a>. This license applies only to original text and images by Patricia Kelly. For permission to use work attributed to others herein, those authors/artists will need to be contacted.</font></em>

http://tolweb.org/tree?group=Vertebrata&contgroup=Craniata is not well-formed XML - see the unclosed <img>:

    <p>
        <a href="http://creativecommons.org/licenses/by/3.0/" target="_blank" rel="license">
                <img src="/tree/img/somerights20.png" class="floatleft"></a>
        <span xmlns:dc="http://purl.org/dc/elements/1.1/" href="http://purl.org/dc/dcmitype/Text" 
            property="dc:title" rel="dc:type">Page: Tree of Life 
        <strong>Vertebrata.  Animals with backbones.</strong></span> 
        Authored by 
        <span xmlns:cc="http://creativecommons.org/ns#" href="http://tolweb.org/Vertebrata/14829/1997.01.01" property="cc:attributionName" rel="cc:attributionURL">Philippe Janvier</span>.
            The <strong>TEXT</strong> of this page is licensed under the 
        <a href="http://creativecommons.org/licenses/by/3.0/" target="_blank" rel="license">
        Creative Commons Attribution License - Version 3.0</a> ...
    </p>

http://mayfly.info/ looks okay in this section (thought the page as a whole is not well-formed XML):

    <div class="blockContent"><!-- Creative Commons License -->
    <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/2.1/jp/">
    <img alt="Creative Commons License" border="0" src="http://i.creativecommons.org/l/by-nc-sa/2.1/jp/88x31.png" class="cc-button"/>
    </a>
    <div class="cc-info">
    <span xmlns:cc="http://creativecommons.org/ns#" xmlns:dc="http://purl.org/dc/elements/1.1/"><span id="work_title" property="dc:title">自由研究のツボxoops</span> by
    <a rel="cc:attributionURL" property="cc:attributionName" href="http://mayfly.info/">ponta</a> is licensed under a
    <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/2.1/jp/">Creative Commons Attribution-NonCommercial-ShareAlike 2.1 Japan License</a>. <span rel="dc:source" href="http://mayfly.info/"/></span>
    </div>
    </div>