I just tried your code but I bound it to object called class1 and it works so fine using this method:
List<MyObject> _list1=new List<MyObject>();
_list1.Add(MyDal.GetObject(myID));
RadGrid1.DataSource=_list1;
RadGrid1.DataBind();
the reason is Grid Should only be bound to IListSource, IEnumerable, or IDataSource.
Regards