using detailsview to insert only

i have the following code:
  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        DetailsView1.DefaultMode = DetailsViewMode.Insert
        DetailsView1.AutoGenerateInsertButton = True
    End Sub
the inserting event for the detailsview's objectsource isn't firing.  anybody run into this?
thanks,

 
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