datatable print complex header print preview

hi im working with datatable and its great but i have problem thats in complex header like this

<thead>
    <tr><td>some text</td></tr>
    <tr><td>some text</td></tr>
</thead>

now in showing page its like like this when i hit print preview i gat result like this

that the first tr in thead is gone i opened datatable.js file and i found this

        var addRow = function ( d, tag ) {
        var str = '<tr>';

        for ( var i=0, ien=d.length ; i<ien ; i++ ) {
            // null and undefined aren't useful in the print output
            var dataOut = d[i] === null || d[i] === undefined ?
                '' :
                d[i];
            var classAttr = columnClasses[i] ?
                'class="'+columnClasses[i]+'"' :
                '';

            str += '<'+tag+' '+classAttr+'>'+dataOut+'</'+tag+'>';
        }

        return str + '</tr>';
    };

    // Construct a table for printing
    var html = '<table class="'+dt.table().node().className+'">';

    html += '<thead>';

    // Adding logo to the page (repeats for every page while print)
    if(config.repeatingHead.logo) {
        var logoPosition = (['left','right','center'].indexOf(config.repeatingHead.logoPosition) > 0) ? config.repeatingHead.logoPosition : 'right';
        html += '<tr><th colspan="'+data.header.length+'" style="padding: 0;margin: 0;text-align: '+logoPosition+';"><img style="'+config.repeatingHead.logoStyle+'" src="'+config.repeatingHead.logo+'"/></th></tr>';
    }

    // Adding title (repeats for every page while print)
    if(config.repeatingHead.title) {
        html += '<tr><th colspan="'+data.header.length+'">'+config.repeatingHead.title+'</th></tr>';
    }

    if ( config.header ) {
        html += addRow( data.header, 'th' );
    }

    html += '</thead>';

    html += '<tbody>';
    for ( var i=0, ien=data.body.length ; i<ien ; i++ ) {
        html += addRow( data.body[i], 'td' );
    }
    html += '</tbody>';

    if ( config.footer && data.footer ) {
        html += '<tfoot>'+ addRow( data.footer, 'th' ) +'</tfoot>';
    }
    html += '</table>';

and its just add the last tr in thead but i couldn't put the first tr with print preview thanks a lot

from datatable print complex header print preview