Hide column when using server side

Hi Allan, nice to talk with you again.

Three years ago I made a webpage with ajax call to server side and hide columns wasn't a problem. (1.4.3)

Now I using 1.9.3 and testing the server side example:
http://datatables.net/release-datatables/examples/server_side/server_side.html

but when I try to hide some column I get an empty table when using

"bVisible": false

but if I use

"bVisible": true

it show all the data.
This is the error I get on firefox debug

Fecha: 23/08/12 21:04:16
Error: TypeError: a.charCodeAt is not a function
Archivo Fuente: http://template/java/jquery.dataTables.min-1.9.3.js
Línea: 83

This is the javascript code I use:

<script type="text/javascript" charset="utf-8">
/***************** recorta el text a n caracteres si esta muy largo   */
//var oTable;
function ellipsis(text, n) {
			if(text.length>n)
				return text.substring(0,n)+"...";
			else
				return text;
		}
/***************** fin recortar ***************************************/

	$(document).ready(function() {
		$('#cuentas').dataTable( {
		/************  funcion para recortar los nombres largos, llama a la funcion que esta hasta arriba ********/    
		/*            
			"fnRowCallback": function( nRow, aData, iDisplayIndex ) {
					var $cell=$('td:eq(1)', nRow);
					$cell.text(ellipsis($cell.text(),30));
					return nRow;
			},
		*/
		/***********  fin funcion para recortar los nombres largos, llama a la funcion que esta hasta arriba *****/                
			"bJQueryUI": true,
			"sPaginationType": "full_numbers",
			"bStateSave": true, // guarda en una cookie todos los parametros de la tabla
			"iCookieDuration": 5, // segundos que se guardara la cookie con los parametros			
			"bProcessing": true,
			
			// parametros de las columnas
			
			"aoColumnDefs": [
					{ "bVisible": false, "aTargets": [ 2 ] }
				],
			
			// fin parametros de las columnas			
			"bServerSide": true,
			"sAjaxSource": "cuentasxcobrar/miscuentas",
			"oLanguage": {						
							"sProcessing": "Procesando...", //
							"sLengthMenu": "Mostrar _MENU_ registros",
							"sZeroRecords": "No se encontraron resultados",
							"sInfo": "Mostrando desde _START_ hasta _END_ de _TOTAL_ registros",
							"sInfoEmpty": "Mostrando desde 0 hasta 0 de 0 registros",
							"sInfoFiltered": "(filtrado de _MAX_ registros en total)",
							"sSearch": "Buscar en todo:",
							"sLoadingRecords": "Please wait - loading...",
							//"sSearch": "Buscar:",
							"oPaginate": {
									"sFirst":    "Primero",
									"sPrevious": "Anterior",
									"sNext":     "Siguiente",
									"sLast":     "&uacute;ltimo"
								}
						},
			/* row click function */			
			"fnDrawCallback": function() {
				$("#cuentas tbody tr").click(function () { 
						var nTds = $('td', this);
						var cuenta = $(nTds[2]).text();
						//var sGrade = $(nTds[4]).text();
						//alert(sBrowser);
						window.location.href = "http://servicobros/index.php/cuentasxc/detallecuenta/"+cuenta;
				} );
				}
			/* end row click function */
													
		} );
	} );
</script>

And this is the server response I ge in both bVisible: false and bVisible: true

{"sEcho":0,"iTotalRecords":"59","iTotalDisplayRecords":"59","aaData":[["Trident","Internet Explorer 4.0","Win 95+","4","X"],["Trident","Internet Explorer 4.0","Win 95+","4","X"],["Trident","Internet Explorer 5.0","Win 95+","5","C"],["Trident","Internet Explorer 5.5","Win 95+","5.5","A"],["Trident","Internet Explorer 6","Win 98+","6","A"],["Trident","Internet Explorer 7","Win XP SP2+","7","A"],["Trident","AOL browser (AOL desktop)","Win XP","6","A"],["Gecko","Firefox 1.0","Win 98+ \/ OSX.2+","1.7","A"],["Gecko","Firefox 1.5","Win 98+ \/ OSX.2+","1.8","A"],["Gecko","Firefox 2.0","Win 98+ \/ OSX.2+","1.8","A"],["Gecko","Firefox 3.0","Win 2k+ \/ OSX.3+","1.9","A"],["Gecko","Camino 1.0","OSX.2+","1.8","A"],["Gecko","Camino 1.5","OSX.3+","1.8","A"],["Gecko","Netscape 7.2","Win 95+ \/ Mac OS 8.6-9.2","1.7","A"],["Gecko","Netscape Browser 8","Win 98SE+","1.7","A"],["Gecko","Netscape Navigator 9","Win 98+ \/ OSX.2+","1.8","A"],["Gecko","Mozilla 1.0","Win 95+ \/ OSX.1+","1","A"],["Gecko","Mozilla 1.1","Win 95+ \/ OSX.1+","1.1","A"],["Gecko","Mozilla 1.2","Win 95+ \/ OSX.1+","1.2","A"],["Gecko","Mozilla 1.3","Win 95+ \/ OSX.1+","1.3","A"],["Gecko","Mozilla 1.4","Win 95+ \/ OSX.1+","1.4","A"],["Gecko","Mozilla 1.5","Win 95+ \/ OSX.1+","1.5","A"],["Gecko","Mozilla 1.6","Win 95+ \/ OSX.1+","1.6","A"],["Gecko","Mozilla 1.7","Win 98+ \/ OSX.1+","1.7","A"],["Gecko","Mozilla 1.8","Win 98+ \/ OSX.1+","1.8","A"],["Gecko","Seamonkey 1.1","Win 98+ \/ OSX.2+","1.8","A"],["Gecko","Epiphany 2.20","Gnome","1.8","A"],["Webkit","Safari 1.2","OSX.3","125.5","A"],["Webkit","Safari 1.3","OSX.3","312.8","A"],["Webkit","Safari 2.0","OSX.4+","419.3","A"],["Webkit","Safari 3.0","OSX.4+","522.1","A"],["Webkit","OmniWeb 5.5","OSX.4+","420","A"],["Webkit","iPod Touch \/ iPhone","iPod","420.1","A"],["Webkit","S60","S60","413","A"],["Presto","Opera 7.0","Win 95+ \/ OSX.1+","-","A"],["Presto","Opera 7.5","Win 95+ \/ OSX.2+","-","A"],["Presto","Opera 8.0","Win 95+ \/ OSX.2+","-","A"],["Presto","Opera 8.5","Win 95+ \/ OSX.2+","-","A"],["Presto","Opera 9.0","Win 95+ \/ OSX.3+","-","A"],["Presto","Opera 9.2","Win 88+ \/ OSX.3+","-","A"],["Presto","Opera 9.5","Win 88+ \/ OSX.3+","-","A"],["Presto","Opera for Wii","Wii","-","A"],["Presto","Nokia N800","N800","-","A"],["Presto","Nintendo DS browser","Nintendo DS","8.5","C\/A<sup>1<\/sup>"],["KHTML","Konqureror 3.1","KDE 3.1","3.1","C"],["KHTML","Konqureror 3.3","KDE 3.3","3.3","A"],["KHTML","Konqureror 3.5","KDE 3.5","3.5","A"],["Tasman","Internet Explorer 4.5","Mac OS 8-9","-","X"],["Tasman","Internet Explorer 5.1","Mac OS 7.6-9","1","C"],["Tasman","Internet Explorer 5.2","Mac OS 8-X","1","C"],["Misc","NetFront 3.1","Embedded devices","-","C"],["Misc","NetFront 3.4","Embedded devices","-","A"],["Misc","Dillo 0.8","Embedded devices","-","X"],["Misc","Links","Text only","-","X"],["Misc","Lynx","Text only","-","X"],["Misc","IE Mobile","Windows Mobile 6","-","C"],["Misc","PSP browser","PSP","-","C"],["Other browsers","All others","-","-","U"],["Misc","Dolphin Browser Mini for Android 4.1 Ice Cream Sandwich custom release","Android","2.1","A"]]}

I think the hide columns with aoColumnDefs is on the client side or I have to make some changes to the php server side scritp?

Let me know

Thanks