Sorting a checkbox column

I'm using this great plugin for my tables. I want to sort by a column that is a checkbox. Reading the info and some posts I did this:

In my view page (mvc) I've 12 columns where the 12th is a check box.

Here is how a Init my table:

<script type="text/javascript">
  
  $(document).ready(
        $('table').dataTable({
            "bJQueryUI": true,
            "sPaginationType": "full_numbers",
            "aoColumns": [
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                { "sSortDataType": "dom-checkbox" }]
        })
        );


</script>

I'm also using this for the sorting:

	$.fn.dataTableExt.afnSortData['dom-checkbox'] = function (oSettings, iColumn) {
	    var aData = [];
	    $('td:eq(' + iColumn + ') input', oSettings.oApi._fnGetTrNodes(oSettings)).each(function () {
	        aData.push(this.checked === true ? "1" : "0");
	    });
	    return aData;
	};

When I try to sort that column, I receive the following error:

DataTables warning: (table id='table'): Returned data sort array (col11) is the wrong length. I can't solve it. Help!