adding data to a DropDownLIst

Hey guys, I've placed code in my page_load event to populate a dropdownlist. The problem I'm having is that the data gets placed in my dropdownlist twice. I went and debugged and it is indeed going through the code twice...Any suggestions as to why it's going through the code twice?

Heres the code...
thanks,
eye

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here

If Not Me.IsPostBack() Then
Me.DropDownList1.Items.Add(New ListItem("WEBDDEVL1"))
Me.DropDownList1.Items.Add(New ListItem("WEBDDEVL2"))
Me.DropDownList1.Items.Add(New ListItem("WEBDDEVL3"))
End If

End Sub