ASP.NET Button click event not firing in dynamic user control (VB)

I'm trying to make a self contained user control that is dynamically loaded to a page's UpdatePanel via links on the main page. The problem I am having is that I have never been able to fire the Click event of a button inside of the UserControl. The button should not affect the outer page at all and is simply trying to run a query against a DataGrid within the same UserControl

I have set the ChildrenAsTriggers property of the containing UpdatePanel to false as nothing inside any of these UserControl objects should manipulate anything outside of itself.

Here is what I have:

<asp:UpdatePanel ID="Updater" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="false">
    <ContentTemplate>

    </ContentTemplate>
</asp:UpdatePanel>

In addition, I have a simple asp:Button inside of the dynamically loaded UserControl that will eventually be contained in the UpdatePanel's ContentTemplate:

<asp:Button runat="server" ID="ButtonGo" Text="Go" />

And a click handler in the code behind:

Public Sub ButtonGo_Click() Handles ButtonGo.Click
    //Trying to break here
End Sub    

I've seen many questions regarding this that all deal with non-dynamic, XAML-in-place content, but can't find anything for my situation.

How do I access the click event of the button, or perhaps, what am I setting up incorrectly to prevent the event from occurring?