Input from notification URL empty (in simple Action Service)

Hi,

I made a simple AppCloud Action Service, and my notification URL is being called, but the input JSON that I receive from Eloqua is empty.

I only receive empty curly brackets {} in the post body of the incoming notification URL.

This is the data that I sent to Eloqua in the response of my create URL:

HTTP/1.1 200

{

    "recordDefinition" :

    {

        "ContactID" : "{{Contact.Id}}"

    }

}

So normally I should receive a list of contact ID's, as well as parameters such as "count" etc. Any ideas ?

Many thanks !

Niko