Are there any existing table sorting libraries, or is there a way to configure tablesorter, to sort every two rows? Alternatly, is there a better way to semantially express my table such that standard row sorting will work.

I have an html table that looks something like this

<table>
    <thead>
        <tr>
            <th>Header 1</th>
            <th>Header 2</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>Some Data: 1</td>
            <td>Some More Data:1 </td>
        </tr>
        <tr>
            <td colspan="2">Some text about the above data that puts it in context and visually spans under both of the cells above so as not to create a weird looking table</td>
        </tr>

        <tr>
            <td>Some Data: 2</td>
            <td>Some More Data: 2</td>
        </tr>
        <tr>
            <td colspan="2">Some text about the above data 2 set that puts it in context and visually spans under both of the cells above so as not to create a weird looking table</td>
        </tr>           

    </tbody>
</table>

I'm looking for a way to sort the table such that the table is sorted by the data rows, but the row with the colspan travels with its data and is not sorted separately.