[thelist] ASP.NET dropdownlist error

[Joel D Canfield]

I'm trying to create a form to edit info in the SQL 2005 database. The
code below gives me the error

    'DeptDDL' has a SelectedValue which is invalid because 
     it does not exist in the list of items.
     Parameter name: value

when I click the automatically created 'Edit' button/link.

The SQL query *does* return valid results, one of which matches
*exactly* (no funky spaces or anything) the existing value in this row
of data.

    <asp:SqlDataSource 
        ID="srcDepts" runat="server" 
        ConnectionString="<%$ ConnectionStrings:cnxHelm %>"
        SelectCommand="SELECT id, DeptName FROM Departments ORDER BY
DeptName">
    </asp:SqlDataSource>    

    <asp:TemplateField HeaderText="Dept" SortExpression="DeptName">
        <ItemTemplate>
            <%# Eval("DeptName") %>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:DropDownList 
                ID="DeptDDL" runat="server" 
                DataSourceID="srcDepts"
                DataTextField="DeptName" 
                DataValueField="id"
                AppendDataBoundItems="True" 
                SelectedValue='<%# Bind("DeptName") %>'>
            </asp:DropDownList>
        </EditItemTemplate>
    </asp:TemplateField>

Thoughts?

joel