Notice: Undefined index: sEcho (sEcho is passed in request though)

Upon trying to sort or filter data from a Datatable using the server_side processing script on the example page, I am given the following error:

Notice: Undefined index: sEcho

And the JSON output returned is:

{"sEcho":0,"iTotalRecords":"2","iTotalDisplayRecords":"2","aaData":[["DC2610","3"],["DC2611","3"]]}

This does not make sense to me, because according to the network tab of Chrome, when I try to sort the data a request is handed off with sEcho being equal to 2 as seen below:

http://localhost/people-app/products/auxRoom.php?sEcho=2&sColumns=room%2Ccapacity&iDisplayStart=0&iDisplayLength=25&sSearch=&iSortCol_0=1&sSortDir_0=asc&iSortingCols=1&ajax=products&visibleColumns=0%2C1

The above is made in the form of a GET request. If it matters I am using the Yii framework, though I don't think that is related. I am using the exact code from the server side scripting example, with the MySQL info changed of course (including columns).

Any reason why this may not be working?


Edit:
I am using Datatables and here are the settings that should be being used currently:

	$.fn.eDataTables.defaults = {
		jqxhr: null,
		ajaxUpdate: [],
		pagerClass: 'pager',
		loadingClass: 'loading',
		filterClass: 'filters',
		tableClass: 'items',
		selectableRows: 1,
		editableSelectsRow: true,
		relatedOnlyOption: false,

		ajaxOpts: {},

		bProcessing: true,
		bServerSide: true,
		bStateSave: false,
		bAutoWidth: false,
		bJQueryUI: true,
		sPaginationType: "full_numbers",
		//aaSorting: [[0, "asc"]],
		iDisplayLength: 25,
		editable: {
			string: {},
			integer: {},
			boolean: {}
		},
		buttons: {},
		filterForm: null,
		filterSerializeCallback: function(f){return f.serializeArray();}
	};

Ajax call is made later.