title: ImageButton does not fire a post back on IE10
body: <p>Recently, we tested our products on IE10 and encountered a problem about that server button control “Asp:ImageButton” are not be fired on IE10 with UpdatePanel.
  And the below is the sample code:</p>
  
  <pre><code>&lt;form id="form1" runat="server"&gt;
  &lt;asp:ScriptManager ID="ScriptManager1" runat="server"&gt;
  &lt;/asp:ScriptManager&gt;
  &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server"&gt;
      &lt;ContentTemplate&gt;
          Here is the content.
      &lt;/ContentTemplate&gt;
      &lt;Triggers&gt;
          &lt;asp:AsyncPostBackTrigger ControlID="buttonSubmit" /&gt;
      &lt;/Triggers&gt;
  &lt;/asp:UpdatePanel&gt;
  &lt;br /&gt;
  &lt;br /&gt;
  &lt;asp:Button ID="buttonSubmit" runat="server" ToolTip="Submit" OnClick="buttonSubmit_Click" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>server side:</p>
  
  <pre><code>    protected void buttonSubmit_Click(object sender, ImageClickEventArgs e)
      {
          ScriptManager.RegisterStartupScript(this, this.Page.GetType(), "alert", "alert('It works.')", true);
      }
  </code></pre>
  
  <p>Here are two things which confused me:
  One is the issue only happens when I deployed on IIS and works fine when debugging on VS.
  The two is if I removed the upper two tag “br”, the event would be fired. Besides, if I change the ImageButton to Button, the event also would be fired.</p>
  
  <p>So, I don’t know if I am missing something or misunderstand the life circle of the ImageButton and Button control. 
  Any help would very appreciate.</p>
  
  <p>Test environments: VS2010, IIS 7.5, IE10(10.0.9200.16484)</p>