DataTables callbacks and infinite requests

Hi all,
I'm experiencing the same problem described in this old discussion: http://datatables.net/forums/discussion/2259/fnserverdata-makes-infinite-http-request-when-we-have-the-callback-function/p1.

I'm using (as also described in the old discussion):
- server side processing
- sAjaxSource
- fnServerData
- $.ajax() calls in fnServerData, calling REST services
- callback function.

DataTables version is 1.9.4.