xPath loadHTML gets tripped up on Table element for "unexpected end tag"

I'm gettin开发者_运维知识库g an error when my content contains the table markup below. Here is the error message:

Warning: DOMDocument::loadHTML() [domdocument.loadhtml]: Unexpected end tag : col in Entity, line: 2

Which is referencing this line in my code:

$dom->loadHTML(strtolower($post->post_content));

My content contains this table markup...

<table style="height: 658px;" 
       border="0" 
       cellspacing="0" 
       cellpadding="0" 
       width="472">
    <colgroup>
        <col width="188"></col>
        <col width="590"></col>
    </colgroup>
    <tbody>
        <tr height="20">
            <td width="188" height="20"></td>
            <td width="590"></td>
        </tr>
    </tbody>
</table>

And I'm using this function to parse it...

function doTheParse($heading)
{
global $post;
$content = $post->post_content;
if($content=="") return false;
$keyword = trim(strtolower(rseo_getKeyword($post)));
$dom = new DOMDocument;
$dom->loadHTML(strtolower($post->post_content));
$xPath = new DOMXPath($dom);
switch ($heading)
    {
    case "img-alt": return $xPath->evaluate('boolean(//img[contains(@alt, "'.$keyword.'")])');
    default: return $xPath->evaluate('boolean(/html/body//'.$heading.'[contains(.,"'.$keyword.'")])');
    }
}

I'm just guessing, but since your col elements have no inner value, try using no end tag instead. So, instead of <col width="188"></col> use <col width="188" />