Problema con findbytext en Drop down list

[julianserna]

El code completo del llenado del drop down es:

Dim ds As New DataSet("ds")
Dim da As New SqlDataAdapter("SELECT intIDState, strAbv FROM tblStates ORDER BY strAbv ASC", koconnection2)
Dim dc As SqlCommandBuilder
da.Fill(ds, "tblstates")
dc = New SqlCommandBuilder(da)
ds.Tables(0).TableName = "tblstates"
ddlZips.DataSource = ds.Tables(0)
ddlZips.DataTextField = "strAbv".ToString
ddlZips.DataValueField = "strAbv".ToString
ddlZips.DataBind()

y el codigo con el que trato de buscar es:

If Not ddlZips.SelectedItem Is Nothing Then
ddlZips.SelectedItem.Selected = False
End If
Dim state As String = oleReader("state_s")
ddlZips.Items.FindByText(state).Selected = True

y ahí me genera el error, gracias