jqGrid ASP.NET MVC4 initial sort - asp.net-mvc-4

Question

I'm using jqGrid as TreeGrid with ASP.NET MVC4 and have one problem:
My Model:
OrdersGrid = new JQGrid
{
Columns = new List<JQGridColumn>()
{
new JQGridColumn
{
DataField = "MeasureId",
// always set PrimaryKey for Add,Edit,Delete operations
// if not set, the first column will be assumed as primary key
PrimaryKey = true,
Visible = false,
Sortable = false
},
new JQGridColumn
{
DataField = "Name",
Width = 100,
Sortable = true
},
new JQGridColumn
{
DataField = "Symbol",
Width = 100
},
},
Width = Unit.Pixel(640),
Height = Unit.Percentage(100),
TreeGridSettings = new TreeGridSettings
{
Enabled = true
},
SortSettings = new SortSettings
{
AutoSortByPrimaryKey = false,
InitialSortColumn = "Name",
InitialSortDirection = SortDirection.Asc
}
};
My Controller:
public JsonResult DataRequested()
{
// Get both the grid Model and the data Model
// The data model in our case is an autogenerated linq2sql database based on Northwind.
var gridModel = new NavigatorModel();
...
var hierarchyRows = from measure in measures
select new
{
MeasureId = measure.MeasureId,
Name = measure.Name,
Symbol = measure.Symbol,
//ParentID = measure.ParentMeasureId != null ? measure.ParentMeasureId.ToString() : "",
tree_loaded = true,
tree_parent = measure.ParentMeasureId,
tree_level =LoadAllRowsExpanded_GetRowLevel(measure.ParentMeasureId, measures),
tree_leaf = LoadAllRowsExpanded_IsLeafRow(measure.MeasureId, measures),
tree_expanded = true
};
//var dataModel = new
// return the result of the DataBind method, passing the datasource as a parameter
// jqGrid for ASP.NET MVC automatically takes care of paging, sorting, filtering/searching, etc
return gridModel.OrdersGrid.DataBind(hierarchyRows.AsQueryable());
}
As above you can see that I'm setting the AutoSortByPrimaryKey set to false, but when the page is loaded, grid looks like that:
When I click on one of columns (Name or Symbol) to sort everything becomes fine - the Measure which is wrongly displayed goes under it's parent.
I have tried also with event to sort after "gridInitialize" but also no success.
Any ideas?