Button OnClick event does not fire

I have a multistep form that I'm creating in C#. The controls I want to display in each step are displayed inside of a label, as such:


<asp:Label runat="server" ID="Step1" Visible="false">
misc controls
<asp:Button runat="server" ID="Continue1" OnClick="Continue1_Click" />
</asp>

<asp:Label runat="server" ID="Step2" Visible="false">
misc controls
<asp:Button runat="server" ID="Continue2" OnClick="Continue2_Click" />
</asp>

I have four steps like the ones above and then the final code to submit all the information. Each step has its own button. The OnClick for the first four buttons is firing perfectly. It hides the label for the step that was just completed and displays the new one. But when I get to the very last button, the On ...