/// 
/// 
/// 

Sys.Application.add_init(function()
{
    $create(Sys.UI.DataGrid,
    {
        alternateRowClass: "odd",
        columnExpressions: ["Title", "FirstName", "MiddleName", "LastName", "Suffix"],
        dataProvider: $create(Sys.Data.AdoNetDataContext, { serviceUri: "AdventureWorks.svc" }),
        itemPlaceholder: $get("customer-placeholder"),
        fetchOperation: "Customers",
        fetchParameters: { $top: 20, $orderby: "FirstName" }
    },
    null,
    null,
    $get("customer-list"));
    
});

I am not sure if this say anything but it might indicate that the dataview has been changed a little. Try typing this into the javascript editor to gain some insight. I got this from the samples download on msdn. http://msdn.microsoft.com/en-us/library/bb514232(VS.100).aspx">http://msdn.microsoft.com/en-us/library/bb514232(VS.100).aspx

var dv = new Sys.UI.DataView();

when you type dv. the intellisense should give you some more information.

 fetchOperation: "Customers",
 fetchParameters: { $top: 20, $orderby: "FirstName" }

... would be my first guess.