Created Unassigned: Accordion Breaks child UpdatePanel with UpdateMode = Conditional [27975]

I have a project that targets .net framework 4.5. The following displays the problem. UpdatePanel2's update mode is set to conditional and is inside an accordion pane. When LinkButton is clicked, the time should update to reflect the current time in the textbox, but UpdatePanel2 does not update. When accordion is removed, leaving just UpdatePanel2 inside the tabcontainer, the textbox is updated accordingly.

<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="False">
<ContentTemplate>
<ajaxToolkit:TabContainer ID="TabContainer1" runat="server" Height="200px">
<ajaxToolkit:TabPanel ID="testtab" runat="server" HeaderText="Tab 1">
<ContentTemplate>
<ajaxToolkit:Accordion ID="Reports" runat="server" HeaderCssClass="accordionHeader" HeaderSelectedCssClass="accordionHeaderSelected"
ContentCssClass="accordionContent" CssClass="accReports" TransitionDuration="250">
<Panes>
<ajaxToolkit:AccordionPane ID="accProject_Time_Report" runat="server" ContentCssClass="" HeaderCssClass="">
<Header>Employee Time</Header>
<Content>
<asp:Panel ID="Panel1" runat="server">
<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:LinkButton ID="LinkButton1" runat="server">LinkButton</asp:LinkButton>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
</Content>
</ajaxToolkit:AccordionPane>
</Panes>
</ajaxToolkit:Accordion>
</ContentTemplate>
</ajaxToolkit:TabPanel>
</ajaxToolkit:TabContainer>
</ContentTemplate>
</asp:UpdatePanel> </asp:Panel>
</ContentTemplate>
</ajaxToolkit:TabPanel>
</ajaxToolkit:TabContainer>
</ContentTemplate>
</asp:UpdatePanel>

Code Behind:

Protected Sub LinkButton1_Click(sender As Object, e As EventArgs) Handles LinkButton1.Click
TextBox1.Text = Date.Now
'UpdatePanel2.Update()
End Sub