UpdatePanel + Timer = Not Working

[GenJerDan]

A simple asp.net page: GridView in an UpdatePanel with a timer to refresh the data every minute. Works Fine On My Machine, hitting IIS Express. Doesn't ever refresh when deployed to the actual IIS server. It just sits there and laughs at me. I've tried various combinations of Timer outside the UpdatePanel with the AsynPostBackTrigger set, Timer inside UpdatePanel with no trigger set. Timer tick explicitly saying to update the UpdatePanel. Etc etc etc, just like the two million Google hits suggest, to no avail. Every "fix" works fine on my machine. It just refuses to work on the server. Is there an IIS setting of some sort that might be causing it? Elsewhere on the page (outside the UpdatePanel) is a Panel with the CollapsiblePanel extender tacked on which works fine, so it isn't a matter of Ajax not being there. Looking at the webpage source from the server and from VS, I see no differences other than the extra crap VS puts in when hosting. relevent code:

<asp:Timer ID="Timer1" runat="server" OnTick="Timer1_Tick" Interval="60000" Enabled="true" EnableViewState="False">
</asp:Timer>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" ChildrenAsTriggers="false" UpdateMode="Conditional" EnableViewState="False">

                        <Triggers>

                            <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />

                        </Triggers>

                        <ContentTemplate>
                            <asp:Label ID="lblLast" runat="server" Text="Newest Order: (waiting for update)" EnableViewState="False"></asp:Label>

                            <asp:Label ID="lblStatus" runat="server" Text="Checking for orders..." Visible="False" EnableViewState="False"></asp:Label>
                            <div class="Refreshed">
                                <asp:Label ID="lblRefresh" runat="server" CssClass="Refreshed" Text="Last Refreshed:" EnableViewState="False"></asp:Label>
                            </div>
                            <br />