SelectedIndexChange event won't get fired,ASP.NET DropDownList - asp.net

Question

I have a Windows form with 1 DataGrid which has a Dropdownlist in one of its columns.
I also have another dropDownlist outside of this DataGrid.
Both of these dropdowns are bound to same dataset and both get populated with same items.
Both of DropDowns have their Autopostbacks set to true.
Problem is only for the dropdownlist Outside of Datagrid SelectedIndexChange Event gets fired:
(I have seen multiple similar questions on SO but none of suggestions works for me. So I really appreciate if you can help me here.
)
Protected Sub ABCD(ByVal sender As System.Object, ByVal e As System.EventArgs)
End Sub
For both Dropdownlists: AutoPostBack="True"
Here is Vb code:
Imports System.Data.OleDb
Public Class WebForm1
Inherits System.Web.UI.Page
Protected WithEvents dg As New System.Web.UI.WebControls.DataGrid
Private cnDB As New OleDbConnection
Private ds As New DataSet
Private daDB As New OleDbDataAdapter
Protected allNames As New DataSet
Protected MyDataSet As DataSet
Protected WithEvents DropDownList1 As System.Web.UI.WebControls.DropDownList
Protected WithEvents DropDownList2 As System.Web.UI.WebControls.DropDownList
Protected WithEvents ddlName As New System.Web.UI.WebControls.DropDownList
#Region " Web Form Designer Generated Code "
'This call is required by the Web Form Designer.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
End Sub
'NOTE: The following placeholder declaration is required by the Web Form Designer.
'Do not delete or move it.
Private designerPlaceholderDeclaration As System.Object
Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
'CODEGEN: This method call is required by the Web Form Designer
'Do not modify it using the code editor.
InitializeComponent()
End Sub
#End Region
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
MyDataSet = NameBudget()
GridDataLoad()
End Sub
Protected Sub Grid_EditCommand(ByVal source As Object, ByVal e As DataGridCommandEventArgs)
dg.EditItemIndex = e.Item.ItemIndex
dg.DataSource = ds
dg.DataBind()
End Sub
Protected Sub Grid_CancelCommand(ByVal source As Object, ByVal e As DataGridCommandEventArgs)
dg.DataSource = ds.Tables(0).DefaultView
dg.EditItemIndex = -1
dg.DataSource = ds
dg.DataBind()
End Sub
Protected Sub Grid_UpdateCommand(ByVal source As Object, ByVal e As DataGridCommandEventArgs)
End Sub
Private Function GridDataLoad()
ddlName.DataSource = MyDataSet
Dim i As Object = MyDataSet.Tables(0)
ddlName.DataBind()
DropDownList1.DataSource = MyDataSet
DropDownList1.DataBind()
Dim strCon As String = _
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\AccessTestDataBases\TestDB.mdb; "
Dim cnDB As New OleDbConnection(strCon)
cnDB.Open()
daDB = New OleDbDataAdapter("Select * from [Persons]", cnDB)
daDB.Fill(ds, "tbl1")
Dim j As Object = ds.Tables(0)
dg.DataSource = ds
dg.DataBind()
cnDB.Close()
Dim ii As Object = ds.Tables(0)
End Function
Protected Function NameEditable(ByVal n As String) As Boolean
Return True
End Function
Protected Function NameBudget() As DataSet
Dim strCon As String = _
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\AccessTestDataBases\TestDB.mdb; "
Dim cnDB As New OleDbConnection(strCon)
cnDB.Open()
daDB = New OleDbDataAdapter("Select ID,Name from [Persons]", cnDB)
Dim ds As New DataSet
daDB.Fill(ds, "tbl1")
cnDB.Close()
Return ds
End Function
Sub SetDefaultListItem(ByVal sender As Object, ByVal e As System.EventArgs)
'*************************************************************************
'* Use this sub to set the Default List for DropDown Listboxes *
'*************************************************************************
Try
If Len(sender.DefaultValue) > 0 Then
If sender.Items.FindByValue(sender.DefaultValue).ToString.Length > 0 Then
sender.Items.FindByValue(sender.DefaultValue).Selected = True
End If
End If
Catch ex As System.Exception
'Throw New System.Exception(ex.ToString())
End Try
End Sub
Protected Sub ABCD(ByVal sender As System.Object, ByVal e As System.EventArgs)
End Sub
End Class
Here is the HTML for datagrid and Dropdownlists:
<Columns>
<ASP:ButtonColumn Text="Delete" CommandName="Delete"></ASP:ButtonColumn>
<asp:EditCommandColumn ButtonType="LinkButton" UpdateText="Update" CancelText="Cancel"
EditText="Edit"></asp:EditCommandColumn>
<ASP:TemplateColumn HeaderText="Name" SortExpression="FY" HeaderStyle-HorizontalAlign="center" HeaderStyle-Wrap="True">
<ItemStyle Wrap="false" HorizontalAlign="left" />
<ItemTemplate>
<ASP:Label ID="Name" Text='<%# DataBinder.Eval(Container.DataItem, "Name") %>' runat="server"/>
</ItemTemplate>
<EditItemTemplate>
<ASP:DropDownList id="DropDownlist2" datasource="<%# MyDataSet %>" DataTextField= "Name" DataValueField="ID" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ABCD">
</ASP:DropDownList>
</EditItemTemplate>
</ASP:TemplateColumn>
</Columns>
<asp:DropDownList id="DropDownList1"
datasource="<%# MyDataSet %>" DataTextField= "Name"
DataValueField="ID" runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ABCD">
</asp:DropDownList>