FixedColumn table load slowly under IE8

Hi Team,
I got some performance problems when using fixedcolumn table 1.9.4 (jquery 1.8.3) under IE8.
My table is huge and include columns(280) x rows(40). it cost more than 50 seconds initialize my table.
And my IE browser will popup a warning ask me whether to stop the javascript process.
Can we make it load faster? under 10 seconds would be fine. :)

$(document).ready(function(){
var start = new Date().getTime();
var oTable = $('#table1').dataTable({
"sScrollX": "100%",
"sScrollY": "300px",
"bPaginate": false
});
new FixedColumns( oTable );
var end = new Date().getTime();
alert((end-start)/1000);

});

Thanks for your help.