controlX has a SelectedValue which is invalid because it does not exist in the list o

I am trying to create a drop down list that is dependent on another
dropdown list value.

I have seen this site
http://www.webswapp.com/codesamples...ts/default.aspx

but I am unable to get it working.  The only things that I have
different is that the displayed text in both list is a text value and
the value is an integer and also I am using the insertitemtemplate.  I
have played with changing from selectedvalue to selected index, but no
dice.

Here is a code snippet:

<asp:FormView ID="FormView1" runat="server" DataKeyNames="ServerID"
DataSourceID="DS_Servers" OnItemUpdating="FormView1_ItemUpdating">
<InsertItemTemplate>
<asp:SqlDataSource ID="DS_Rack" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString1 %>"
SelectCommand="SELECT [RackID], [Rack] FROM
[cRack]"></asp:SqlDataSource>
<asp:SqlDataSource ID="DS_Cabinet" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString1 %>"
SelectCommand="SELECT [CabinetID], [Cabinet] FROM
[cCabinet] WHERE ([RackID] = @RackID)">
<SelectParameters>
<asp:ControlParameter ControlID="ddRack" Name="RackID"
PropertyName="SelectedValue" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
<table>
<tr align="left">
<td>Rack Location</td>
<td>
<asp:DropDownList ID="ddRack" runat="server"
AutoPostBack="True" SelectedValue='<%# Bind("RackID") %>'
DataSourceID="DS_Rack" DataTextField="Rack"
DataValueField="RackID"></asp:DropDownList>
-
<asp:DropDownList ID="ddCabinet" runat="server"
SelectedValue='<%# Eval("CabinetID") %>' DataSourceID="DS_Cabinet"
DataTextField="Cabinet" DataValueField="CabinetID"
OnDataBound="ddCabinet_DataBound">
</asp:DropDownList>
</td>
</tr>
<tr>
<td>
<asp:LinkButton ID="InsertButton" runat="server"
CausesValidation="True" CommandName="Insert"
Text="Insert"></asp:LinkButton>
<asp:LinkButton ID="InsertCancelButton"
runat="server" CausesValidation="False" CommandName="Cancel"
Text="Cancel"></asp:LinkButton>
</td>
</tr>
</table>
</InsertItemTemplate>
</asp:FormView>


Protected Sub FormView1_ItemUpdating(ByVal sender As Object, ByVal
e As FormViewUpdateEventArgs)
Dim Rack As Integer = CType(CType(sender,
FormView).FindControl("ddCabinet"), DropDownList).SelectedIndex
e.NewValues("Rack") = Rack
e.Cancel = False
End Sub
Protected Sub ddCabinet_DataBound(ByVal sender As Object, ByVal e
As EventArgs)
Dim ddl As DropDownList = CType(sender, DropDownList)
Dim frmV As FormView = CType(ddl.NamingContainer, FormView)
If Not frmV.DataItem Is Nothing Then
Dim RackID As Int32 = CType(frmV.DataItem,
Data.DataRowView)("Rack")
ddl.ClearSelection()
Dim li As ListItem = ddl.Items.FindByValue(RackID)
If Not li Is Nothing Then li.Selected = True
End If
End Sub

Any help would be greatly appreciated.