jQuery tablesorter filter and zebra widgets stop working after ajax update IE8 only

Question

I am updating a table dynamically using versions jquery-1.7.2.min, TableSorter 2.7.12 min, tableSorter 2.4+ widgets - updated 2/24/2013.

The code works fine in IE9 and Chrome but in IE8 the filter and zebra widgets stop working after an ajax update, the sort still works.

<table class="tablesorter">
    <thead>
        <tr>
            <th style="width: 145px;">Orig_Time</th>
            <th style="width: 145px;">Corra_Time</th>
            <th style="width: 120px;">Site</th>
            <th style="width: 120px;">Area</th>
            <th>Reference</th>
        </tr>
    </thead>
    <tbody>
    </tbody>
</table>

$(document).ready(function() {
 $("table").tablesorter({
    sortList: [[0, 1]],
    widthFixed: true,
    theme: 'green',
    widgets: ["filter", "stickyHeaders"],
    widgetOptions: {
        stickyHeaders: "tablesorter-stickyHeader",
        filter_cssFilter: "tablesorter-filter",
        filter_hideFilters: false,
        filter_functions: {
            3: {
                "Midlands+North": function(f) {
                    return f === "Midlands" | f === "North";
                },
                "Scotland+NI": function(f) {
                    return f === "Scotland" | f === "N.Ireland";
                },
                "South+East": function(f) {
                    return f === "South" | f === "East";
                },
                "Wales+West": function(f) {
                    return f === "Wales" | f === "West";
                },
                "Mid+Nor+Sco+NI": function(f) {
                    return f === "Midlands" | f === "North" | f === "Scotland" | f === "N.Ireland";
                },
                "Sou+Eas+Wal+Wes": function(f) {
                    return f === "South" | f === "East" | f === "Wales" | f === "West";
                }
            }
        }
    }
 });
});

function alarms() {
 $("table tbody").load("includes/alarmsResults.php", function() {
    $("table").trigger("update");
 });
}

window.setInterval(alarms, 10000);

alarmsResults.php just runs an sql query and returns the results in <tr><td> tags.

IE8 works fine with the plugins if the data is static but after an update filter and zebra stop working. Any ideas please?

I have tried with tableSorter 2.1 widgets - updated 4/2/2012 and the old filter and it works but it does not have the custom filter options.

Cheers.