Hello all programmers

I'm having trouble that I don't know if its a bug or my fault. Here is my code:

jQuery("#detFlex1").jqGrid('editGridRow',"new",{top:top,left:left,width:width,height:height,reloadAfterSubmit:false,closeAfterAdd:true,addedrow:"last",bSubmit:"Add",onClose: function(){calculatePriority()} });

What I'm trying to do is making newly added rows to appear at the bottom. But it seems 'addedrow' property doesn't make any difference. New data keeps being added at the top.

Am I missing something here?