sScrollY ignored completely

Hi,

I am trying to make the table body scrollable using sScrollY, but this parameter makes no difference whatsoever to the appearance of the table.

Here is the table initialization code:

oTable = $('#tablewidget').dataTable(
{
"bAutoWidth": false,

"aoColumns":
[
{ "sWidth" : "5%", "bSortable": "false" },
{ "sWidth" : "10%", "iDataSort" : 8 },
{ "sWidth" : "17%" },
{ "sWidth" : "15%" },
{ "sWidth" : "15%", "sType": "listTypeCount" },
{ "sWidth" : "15%" },
{ "sWidth" : "12%" },
{ "sWidth" : "22%" },
{"bVisible" : false}


],
"sScrollY": "200px", // ********* Scrolling parameter
"aaSorting": [[1,'desc']],
"sPaginationType": "full_numbers",
"sDom": '<"top"p>f',
"oLanguage": {
"sSearch":'<span style="float: left; padding-left:20px;margin-top:10px;">Search for:&nbsp;</span>',
"oPaginate": {
"sNext" : "Next",
"sPrevious" : "Prev."
}
}
,"iDisplayLength": 10 //control how many records per page to display. Defaulting to 10

}
);

Any help appreciated!

Thanks