Nested GridView Row Event Pandemonium

I have come across odd behavior involving nested gridview controls and row events. Basically the nested gridview row event will not fire unless it is in the last row of the outer grid. If you explicitly add the row event property to the markup (e.g. OnRowDeleted="gvInner_RowDeleted") then the row event fires for all nested gridviews however it fires twice for the nested gridview in the last row of the outer gridview EDIT: I should note that I am using the SqlDataSource for the outer gridview as it is also editable. This isn't clear in the example.

Markup:
<asp:GridView ID="gvOuter" DataSourceID="sdsOuter" runat="server" OnRowDatabound="DynamicControlAdder" AutoGenerateColumns="false">
<Columns>
<asp:BoundField DataField="Id" ReadOnly="true" />
<asp:TemplateField>
<ItemTemplate>
<asp:UpdatePanel ID="upInner" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="gvInner" DataSourceId="sdsInner" runat="server" DataKeyNames="Id" AutoGenerateColumns="false">
<Columns>
<asp:CommandField ShowDeleteButton="true" />
<asp:BoundField DataField="Id" />
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="sdsInner" runat="server"
ProviderName="<%$ ConnectionStrings:YourString.ProviderName %>"
ConnectionString="<%$ ConnectionStrings:YourString %>"
SelectCommand="SELECT * FROM tblInner WHERE OuterTableKey = @OuterTableKey"
DeleteCommand="DELETE FROM tblInner WHERE Id = @Id">
<SelectParameters>
<asp:Parameter Name="OuterTableKey" DefaultValue="0" Type="Int32" />
</SelectParameters>
<DeleteParameters>
<asp:Parameter Name="Id" DefaultValue="0" Type="Int32" />
</DeleteParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="sdsOuter" runat="server"
ProviderName="<%$ ConnectionStrings:YourString.ProviderName %>"
ConnectionString="<%$ ConnectionStrings:YourString %>"
SelectCommand="SELECT * FROM tblOuter">
</asp:SqlDataSource>
Code:
Partial Class Testing
Inherits System.Web.UI.UserControl
Protected Sub DynamicControlAdder(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
If e.Row.RowType <> DataControlRowType.DataRow Then
Exit Sub
End If
Dim s As SqlDataSource = CType(e.Row.FindControl("sdsInner"), SqlDataSource)
s.SelectParameters("OuterTableKey").DefaultValue = e.Row.DataItem("Id").ToString()
End Sub
Protected Sub gvInner_RowDeleted(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewDeletedEventArgs) Handles gvInner.RowDeleted
//'This never fires unless it is the last row in the outer gridview
//'also, if this event is declared in the OnRowDeleted property of the inner gridview, this event fires twice if it is in the last row of the outer grid
Dim strFoo As String = "Foo"
End Sub
End Class