jQuery Grid Plugin - jqGrid

Hi:

I'm trying to use inline Nav "add new row" functionality for a jQGri Treegrid, so far i'm not able to configure it properly. i've read teh documentationa nd oteh rposts related to it but nothing is working.

I've set the options for addRow but whne i click teh add row icon, a new row is added in the grid and an erro pops out "Uncaught TypeError: Cannot read property 'length' of null jquery.jqGrid.src.js:8963″. Any thoughts on this? I've successfully configured teh inliene edit and its working fien for me but nlien add is not workinga s expected!

I've checked the jqgrid src, the error comes in this snippet

if (treeg) { $("span:first",this).html(""); }
else { $(this).html(""); }
var opt = $.extend({},cm[i].editoptions || {},{id:rowid+"_"+nm,name:nm});
if(!cm[i].edittype) { cm[i].edittype = "text"; }
if(tmp == " " || tmp == " " || (tmp.length==1 && tmp.charCodeAt(0)==160) ) {tmp='';}

this code is looking for span in the column but when i checked the column through firebug, there is no span tag rendered in the markup of that column

Any thoughts on this?