[jQuery] $(document).ready script appears to not run in IE?

[Billy]

Hello all,

I'm relatively new to jQuery, and I'm having some trouble making a
selected <tbody> display in IE. It seems to work fine in FireFox, and
Chrome.

See here:

http://wwwdev.latrobe.edu.au/nursing/ProspectiveStudents/Postgraduate2009/questionnaire/index.php

I've looked up various fora, but the only things I can find seem to
relate to earlier versions of jQuery. We're running jQuery-min.1.3.2
on this site.

The relevant parts of the code which run in FF/Chrome, but appear to
not run in IE:

<script language="javascript" type="text/javascript">
$(document).ready(function()
{
    //...
        $('#questionTable tbody:first').addClass('selected');

   //...

});
</script>

Relevant CSS associated with this:

<style>
#questionTable tbody {
        display: none;
}
#questionTable tbody.selected {
        display:table;
}
</style>

Help?

Thanks in advance,

Billy