jQuery Grid Plugin - jqGrid

I am loading a treegrid using local data. For some reason, jqGrid is displaying cell values

based on "name" property and not "jsonmap" property of the colModel.

Here is a simplified version of the grid and the local data. With the below configuration,

I get empty values in the "Qty" column. However, if in "mydata" I change "qty1″ to "qty"

I get values in the "Qty" column.

var mydata =  {"rows":[
    {id: 1221,name: "P1",qty1: "1", level: 0,parent: "NULL",isLeaf: false, 
loaded: true, expanded: true},
    {id: 1222,name: "P1-Child",qty1: "2", level: 1,parent: 1221,isLeaf: true, 
loaded: true, expanded: true}
]};

jQuery("#bomTable").jqGrid({
       treeGrid:true,
       treeGridModel:'adjacency',
       ExpandColumn:'name',
       treedatatype: "local",
       datatype: "local",
       data: mydata,
       jsonReader: {
           repeatitems: false
       },
       colNames:['ID', 'Name', 'Qty'],
       colModel:[
           {name:'id', hidden: true},
           {name:'name', index:'name'},
           {name: 'qty', jsonmap: 'qty1', index: 'qty'}
       ],
       width:'auto',
       height:'auto',
       shrinkToFit:false
   });

   jQuery("#bomTable")[0].addJSONData({
       total: 1,
       page: 1,
       records: mydata.rows.length,
       rows: mydata.rows
   }) ;

Would greatly appreciate any inputs!