$("#grid tbody tr").click(function(e) {
    if (e.target.type == "checkBox") {

        // stop the bubbling to prevent firing the row's click event
        e.stopPropagation();
    } else {
        var $checkBox = $(this).find(':checkBox');
        $checkBox.attr('checked',!$checkBox.attr('checked'));
    }
});

http://jsfiddle.net/karim79/UX2Fv/