As a follow up... The same error seems to occur on InsertItemTemplate on listview.
Here is what I attempted:
<InsertItemTemplate>
<tr>
<td>
Rag Status
<asp:DropDownList ID="ddlRagStatusIdInsert" runat="server" DataSourceID="dsRagStatus"
SelectedValue='<%# Bind("RagStatusId") %>'
DataTextField="DescrShort" DataValueField="RagStatusId" AppendDataBoundItems="true">
<asp:ListItem Text="-Select-" Value="" Enabled="True"></asp:ListItem>
</asp:DropDownList>
</td></tr> etc...
I have got around this with:
Private Sub lvIssue_ItemInserting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ListViewInsertEventArgs) Handles lvIssue.ItemInserting
e.Values("LastUpdate") = Now.ToString
e.Values("LastUpdateBy") = HttpContext.Current.User.Identity.Name
' Grab selected value rather than binding with SelectedValue='<%# Bind("RagStatusId") %>'
e.Values("RagStatusId") = CType(CType(sender, ListView).InsertItem.FindControl("ddlRagStatusIdInsert"), DropDownList).SelectedValue
End Sub
Hope this helps someone!