Trecho referente a classe Zend_Service_SlideShare, houve mudanças na API e alguns nomes das tags do XML estão diferentes.

SlideShare.php

protected function _slideShowNodeToObject(SimpleXMLElement $node)
{

    if($node->getName() == 'Slideshow') {
        $ss = new Zend_Service_SlideShare_SlideShow();

        $ss->setId((string)$node->ID);
        $ss->setDescription((string)$node->Description);
        $ss->setEmbedCode((string)$node->Embed); // changed
        $ss->setNumViews((string)$node->Views);
        $ss->setPermaLink((string)$node->URL); // changed
        $ss->setStatus((string)$node->Status);
        $ss->setStatusDescription((string)$node->StatusDescription);

        foreach (explode(",", (string)$node->Tags) as $tag) {
            if (!in_array($tag, $ss->getTags())) {
                $ss->addTag($tag);
            }
        }

        $ss->setThumbnailUrl((string)$node->ThumbnailURL); // changed
        $ss->setTitle((string)$node->Title);
        $ss->setLocation((string)$node->Location);
        $ss->setTranscript((string)$node->Transcript);

        return $ss;
    }

    require_once 'Zend/Service/SlideShare/Exception.php';
    throw new Zend_Service_SlideShare_Exception(
        'Was not provided the expected XML Node for processing'
    );
}