jQuery form submission issues in IE11

Question

We've been having a bug where (only some, not all) users on IE11 are unable to submit a form that uses a jQuery event to trigger the submission. The page has a submit button with a click event handler that triggers a bootstrap modal, with a message for the user, and when the user clicks a confirm button in the modal, a submit event handler should trigger the form submission. Users in Chrome/FF have reported no issues, and we've been unable to replicate this issue locally, on any browser (including IE).

The code is as follows:

<!-- FORM CODE -->
<form id="my-form" action="." method="post">
    ...

    <input type="submit" id="update" value="Update Request">
</form>

<!-- BOOTSTRAP MODAL CODE -->
<div id="my-modal" class="modal hide fade">
    <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        <h3>Title</h3>
    </div>
    <div class="modal-body">
        <p>Modal Message</p>
    </div>
    <div class="modal-footer">
        <button id="confirm">Confirm</button>
        <button data-dismiss="modal" aria-hidden="true">Close</button>
    </div>
</div>

//JS CODE (This lives in a separate js static file)
$(document).on('click', '#update', function() {
    $('#my-modal').modal('show');
    return false;
});

$(document).on('click', '#confirm', function() {
    $('#my-form').submit();
});

Any ideas on what could be causing problems for the IE11 users?

The site is using jQuery 1.8.3, bootstrap 2.3.2.