I'm able to use addRowData add a single object at a position. However, when I try to add an array of objects, they are always appended, regardless of the position parameter.  

E.g. Given: 

        var mydata = [ {  "item":1,"title":"A title", "amount":"1240", "mydate":"02.21.13", "mydate2":"02.21.13"},
   	               {  "item":2,"title":"A second title", "amount":"100.02", "mydate":"01.21.13", "mydate2":"01.21.13" } ];
  	var mydata3 = {  "item":3,"title":"A third title", "amount":"1240", "mydate":"02.21.13", "mydate2":"02.21.13"} ;
  	var mydata4 = {  "item":4,"title":"A fourth title", "amount":"100.02", "mydate":"01.21.13", "mydate2":"01.21.13" } ;
  	var myMoreData = [ {  "item":5,"title":"A fifth title", "amount":"13000", "mydate":"05.23.13", "mydate2":"05.23.13"},
   	               {  "item":6,"title":"A sixth title", "amount":"120.002", "mydate":"01.21.13", "mydate2":"01.21.13" } ]; 

Then:

	grid.addRowData("item", mydata);
	// Can add individual rows in specific positions
	grid.addRowData(3, mydata3, "first");
	grid.addRowData(4, mydata4, "before", "2");
	// can only append multiple rows
	grid.addRowData("item", myMoreData, "first");