Drop "_iId" from the row model - its not used anywhere in DataTables these days. An old legacy property from the 1.3 days I think - can't imagine any third party plug-ins use this property either - its more or less useless these days.

media/js/jquery.dataTables.js

@@ -1174,7 +1174,6 @@
 			/* Create the object for storing information about this new row */
 			var iRow = oSettings.aoData.length;
 			var oData = $.extend( true, {}, DataTable.models.oRow, {
-				"_iId": oSettings.iNextId++,
 				"_aData": aDataIn
 			} );
 			oSettings.aoData.push( oData );
@@ -1257,8 +1256,7 @@
 					{
 						iThisIndex = oSettings.aoData.length;
 						oSettings.aoData.push( $.extend( true, {}, DataTable.models.oRow, {
-							"nTr": nTrs[i],
-							"_iId": oSettings.iNextId++
+							"nTr": nTrs[i]
 						} ) );
 						
 						oSettings.aiDisplayMaster.push( iThisIndex );
@@ -8617,7 +8615,6 @@
 		 * Purpose:  Store data information
 		 * Scope:    jQuery.dataTable.classSettings 
 		 * Notes:    This is an array of objects with the following parameters:
-		 *   int: _iId - internal id for tracking
 		 *   array: _aData - internal data - used for sorting / filtering etc
 		 *   node: nTr - display node
 		 *   array node: _anHidden - hidden TD nodes
@@ -9190,13 +9187,6 @@
 		 */
 		"nTr": null,
 	
-		/**
-		 * Redundant - drop
-		 *  @type node
-		 *  @default null
-		 */
-		"_iId": null,
-	
 		/**
 		 * Data object from the original data sorce for the row. This is either
 		 * an array if using the tranditional form of DataTables, or an object if

media/src/core/core.data.js

@@ -22,7 +22,6 @@ function _fnAddData ( oSettings, aDataSupplied )
 	/* Create the object for storing information about this new row */
 	var iRow = oSettings.aoData.length;
 	var oData = $.extend( true, {}, DataTable.models.oRow, {
-		"_iId": oSettings.iNextId++,
 		"_aData": aDataIn
 	} );
 	oSettings.aoData.push( oData );
@@ -105,8 +104,7 @@ function _fnGatherData( oSettings )
 			{
 				iThisIndex = oSettings.aoData.length;
 				oSettings.aoData.push( $.extend( true, {}, DataTable.models.oRow, {
-					"nTr": nTrs[i],
-					"_iId": oSettings.iNextId++
+					"nTr": nTrs[i]
 				} ) );
 				
 				oSettings.aiDisplayMaster.push( iThisIndex );

media/src/model/model.row.js

@@ -15,13 +15,6 @@ DataTable.models.oRow = {
 	 */
 	"nTr": null,
 
-	/**
-	 * Redundant - drop
-	 *  @type node
-	 *  @default null
-	 */
-	"_iId": null,
-
 	/**
 	 * Data object from the original data sorce for the row. This is either
 	 * an array if using the tranditional form of DataTables, or an object if

media/src/model/model.settings.js

@@ -98,7 +98,6 @@ DataTable.models.oSettings = {
 	 * Purpose:  Store data information
 	 * Scope:    jQuery.dataTable.classSettings 
 	 * Notes:    This is an array of objects with the following parameters:
-	 *   int: _iId - internal id for tracking
 	 *   array: _aData - internal data - used for sorting / filtering etc
 	 *   node: nTr - display node
 	 *   array node: _anHidden - hidden TD nodes