fnDrawCallBack or initComplete callback is never getting invoked

Santhosh Kalappan

fnDrawCallBack is never invoked

$("#testDT").DataTable({
.
.
"ajax": "someurl'
"fnDrawCallBack" : function(settings) {
.
.
}
}
I use ajax to load data, i do the same thing in one more place. Strangely it works for me from a different place.
Anyhelp would be greatly appreciated.