Undefined/Null reference error in IE8 (I'm stuck)

Hello all -
I am in a pickle and could use some help identifying where my code is going awry. The page functions as intended in all browsers/all versions with the exception of IE8. Here is the demo: https://dl.dropboxusercontent.com/u/12535872/tbl/tbl/index.html

This is what I have building the table (there is a little validation going on in there too)

$(document).ready(function(){
	$('body', window.parent.document).append('<div id="popup_div" style="display:none;"></div>');
	var oTable = $('#tbl').dataTable({
		"bPaginate":true,
		"bFilter":false,
		"bSort":true,
		"aoColumns": [
			{"bSortable":false},
			null,
			null,
			null,
			null,
			null,
			null,
			{"bVisible":false},
			{"bVisible":false},
			
		],
	});
	
	$('#tbl tbody td:nth-child(1)').each(function(){
		$(this).addClass('plus');
	});
	
	$('td.plus').click(function(){
		var nTr = $(this).parents('tr')[0];
        if ( oTable.fnIsOpen(nTr) )
        {
            /* This row is already open - close it */
            $(this).html("[+]");
            oTable.fnClose( nTr );
        }
        else
        {
            /* Open this row */
            $(this).html("[-]");
            oTable.fnOpen( nTr, fnFormatDetails(oTable, nTr), 'details' );
        }
	});
	$('.epr').click(function(){
		var nTr = $(this).parents('tr')[0];
		var aData = oTable.fnGetData( nTr );
		var popup_html = aData[8];
		$('#popup_div', window.parent.document).html(popup_html);
		window.parent.jQuery('#popup_div').bPopup();
		$('.req_epr', window.parent.document).click(function(){
			
			var company = $(this).parent().children('.company').val();
			var full_name = $(this).parent().children('.fullname').val();
			var office_number = $(this).parent().children('.offnum').val();
			var cell_number = $(this).parent().children('.cellnum').val();
			var email_address = $(this).parent().children('.email').val();
			var email_address_confirm = $(this).parent().children('.emailconf').val();
			var trade = $(this).parent().children('.trade').val();
			var toc = $(this).parent().children('.toc').is(':checked');
			var valid = 1;
			if(!company){
				valid=0;
				$(this).parent().children('.company').css('border-color','red');
			}else{
				$(this).parent().children('.company').css('border-color','#BFBFBF');
			}
			if(!full_name){
				valid=0;
				$(this).parent().children('.fullname').css('border-color','red');
			}else{
				$(this).parent().children('.fullname').css('border-color','#BFBFBF');
			}
			if(!office_number){
				valid=0;
				$(this).parent().children('.offnum').css('border-color','red');
			}else{
				$(this).parent().children('.offnum').css('border-color','#BFBFBF');
			}
			if(!cell_number){
				valid=0;
				$(this).parent().children('.cellnum').css('border-color','red');
			}else{
				$(this).parent().children('.cellnum').css('border-color','#BFBFBF');
			}
			if(!email_address){
				valid=0;
				$(this).parent().children('.email').css('border-color','red');
			}else{
				$(this).parent().children('.email').css('border-color','#BFBFBF');
			}
			if(!email_address_confirm){
				valid=0;
				$(this).parent().children('.emailconf').css('border-color','red');
			}else{
				$(this).parent().children('.emailconf').css('border-color','#BFBFBF');
			}
			if(!trade){
				valid=0;
				$(this).parent().children('.trade').css('border-color','red');
			}else{
				$(this).parent().children('.trade').css('border-color','#BFBFBF');
			}
			if(!toc){
				valid=0;
				$(this).parent().children('.tocl').css('background-color','red');
			}else{
				$(this).parent().children('.tocl').css('background-color','transparent');
			}
			if(!valid){return;}
			if(email_address != email_address_confirm){$(this).parent().children('.emailconf').css('border-color','red');return;}
			
			$(this).parents('form').trigger('submit');
			
		});
	});
	
	
	
});

$('#parentPrice', window.parent.document).html();

function fnFormatDetails ( oTable, nTr )
{
    var aData = oTable.fnGetData( nTr );
	return aData[7];
}

Any help would be greatly appreciated.

m