"undefined" group name with row grouping

Rodriguez

I'm trying to group the values in the first column of server-side (json) created table and it appears the fnDrawCallback fuction actually does work since I get no errors and the first column is hidden, but where the groupname should be, "undefined" is stated.

screenshot that should clear things up: http://s16.postimage.org/o5ig167yt/grouping.png

here's me debugger link http://debug.datatables.net/unuwiy

and my js:

[code]

$(document).ready( function() {
var oTable = $('#example').dataTable( {
"sAjaxSource": "json_gespeeldekaartings.php",
"aoColumns": [
{ "mData": "kaarting" },
{ "mData": "speler" },
{ "mData": "punten" }
],
"sAjaxDataProp": "",
"aaSorting": [],

"fnDrawCallback": function ( oSettings ) {
if ( oSettings.aiDisplay.length == 0 )
{
return;
}

var nTrs = $('#example tbody tr');
var iColspan = nTrs[0].getElementsByTagName('td').length;
var sLastGroup = "";
for ( var i=0 ; i

Rodriguez

nobody with similar issues? :(