title: UpdatePanel with ASP.NET Repeater and Checkbox Aync Postback issue
body: <p>I have a rather annoying issue here</p>
  
  <p>I can't get my CheckBox CheckedChange event to fire, or catch or whatever it is that fails:</p>
  
  <p>ASPX Code</p>
  
  <pre><code>&lt;asp:UpdatePanel runat="server" ID="udp_Lists" UpdateMode="Always"&gt;
  &lt;ContentTemplate&gt;
      &lt;asp:Repeater ID="rep_showings" runat="server"&gt;
          &lt;HeaderTemplate&gt;
          &lt;/HeaderTemplate&gt;
          &lt;ItemTemplate&gt;
              &lt;div class="div_assignment"&gt;
                  &lt;div class="div_assignment_text"&gt;
                      &lt;asp:LinkButton runat="server" ID="lnk_show_task" OnClick="lnk_show_task_Click" CommandArgument='&lt;%# Eval("Id") %&gt;' Text='&lt;%# Eval("TaskTitle") %&gt;'&gt;&lt;/asp:LinkButton&gt;
                  &lt;/div&gt;
                  &lt;div class="div_assignment_checkbox"&gt;
                      &lt;asp:CheckBox runat="server" ID="chk_handle" AutoPostBack="true" OnCheckedChanged="chk_handle_Changed" ToolTip='&lt;%# Eval("Id") %&gt;' /&gt;
                  &lt;/div&gt;
              &lt;/div&gt;
          &lt;/ItemTemplate&gt;
          &lt;FooterTemplate&gt;
          &lt;/FooterTemplate&gt;
      &lt;/asp:Repeater&gt;
  &lt;/ContentTemplate&gt;
  &lt;Triggers&gt;
  &lt;/Triggers&gt;
  </code></pre>
  
  <p></p>
  
  <p>The Code behind function <code>"chk_handle_Changed"</code> is never reached.
  The Linkbutten works perfectly.</p>