Gridview UpdatePanel Paging Works, but Not LinkButton

Hello, I have a gridview in an update panel with paging controls.  Inside the gridview, I have a template item with a linkbutton with the command "next".

On deployment, the paging links work with the update panel, but not the linkbutton.

The baffling part is I have another application with the identical page setup, and the update panel works fine with both controls.  Both applications have the triggers setup in the update panel.

I've read that I have to loop thru the rows to find the control, however, why?  The other application is working fine by just dropping the gridview in the update panel and selecting the trigger.  (gridview: PageIndexChanged)

<ItemTemplate><iframe id="I2" height="70" name="I1" src="gvAd.html" style="border-style:none;" width="295"></iframe><br /><asp:Label ID="Label1" runat="server" Text='<%# Bind("firstName")%>'></asp:Label><br /><asp:LinkButton ID="LinkButton2" runat="server" BorderStyle="None" CommandArgument="Next" CommandName="Page"><asp:Image ID="Image2" runat="server" ImageUrl='<%# FormatURL11(DataBinder.Eval(Container.DataItem, "ImgID"))%>' onerror="this.src='images/hsc_splash.gif'"
                                                ToolTip='<%# Bind("firstName")%>' CssClass="tocimg" BorderStyle="None" Height="335px" Width="335px" /></asp:LinkButton><br /><asp:Label ID="Label3" runat="server" Text='<%# Bind("zCode")%>'></asp:Label></ItemTemplate>

<Triggers><asp:AsyncPostBackTrigger ControlID="GridView1" EventName="PageIndexChanged" /></Triggers>