Problema con dropdownlist

[rockout]

sige sin funcionarme, mi codigo es el siguiente:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If Not Page.IsPostBack Then
Me.SqlConnection1.Open()
Me.SqlDataAdapter1.Fill(Me.Ds_tipos1)
Me.SqlConnection1.Close()

Me.Dropdownlist3.DataBind()

Me.Dropdownlist3().Items.Insert(0, "")
'Me.Dropdownlist3.SelectedIndex = 0

If Len(Trim(Request("DropDownList3"))) > 0 Then
Me.Dropdownlist3.SelectedValue = Request("DropDownList3")
End If
End If
End Sub