title: Postback doesn't work with aspx page as Default Document
body: <p>If I browse to <a href="http://localhost/edumatic3/trunk/login/accesscode/Default.aspx" rel="noreferrer">http://localhost/edumatic3/trunk/login/accesscode/Default.aspx</a>, my postback works. However, if I browse to <a href="http://localhost/edumatic3/trunk/login/accesscode/" rel="noreferrer">http://localhost/edumatic3/trunk/login/accesscode/</a> (with Default.aspx defined as default document), my postback doesn't work.</p>
  
  <p>Is there a way to make this work? Or should I remove the default document and force users to browse to <a href="http://localhost/edumatic3/trunk/login/accesscode/default.aspx" rel="noreferrer">http://localhost/edumatic3/trunk/login/accesscode/default.aspx</a>?</p>
  
  <p>UPDATE:</p>
  
  <p>Code (part):</p>
  
  <pre><code>&lt;div id="continueDiv"&gt;
          &lt;asp:ImageButton ID="continueImageButton" 
                  runat="server" ValidationGroup="continue" 
                  OnClick="ContinueImageButton_Click" 
                  AlternateText="&lt;%$ Resources:login, continue_alternatetext %&gt;"/&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>Code behind (part):</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
  {
      Log.Debug("Page_Load(...)");
      Log.Debug("Page_Load(...) :: PostBack = " + IsPostBack);
  
      if (!IsPostBack)
      {
          continueImageButton.ImageUrl = "~/App_Themes/" + base.Theme 
          + "/images/" + Resources.login.btn_continue;
      }
  }
  
  /// &lt;summary&gt;
  /// Continue Image Button Click Handler
  /// &lt;/summary&gt;
  /// &lt;param name="sender"&gt;&lt;/param&gt;
  /// &lt;param name="e"&gt;&lt;/param&gt;
  protected void ContinueImageButton_Click(object sender, EventArgs e)
  {
   ....
  </code></pre>
  
  <p>When I click on the ImageButton, Page_Load is triggered, and IsPostBack is false... Normally, it should be true. ContinueImageButton_Click(...) isn't triggered at all.</p>
  
  <p>In HTML (part):</p>
  
  <pre><code>&lt;input type="image" name="ctl00$ContentPlaceHolder1$continueImageButton" 
  id="ctl00_ContentPlaceHolder1_continueImageButton" 
  src="../../App_Themes/LoginTedu/images/en_continue.png" alt="Continue" 
  onclick="javascript:WebForm_DoPostBackWithOptions(new 
  WebForm_PostBackOptions(&amp;quot;ctl00$ContentPlaceHolder1$continueImageButton&amp;quot;, 
  &amp;quot;&amp;quot;, true, &amp;quot;continue&amp;quot;, &amp;quot;&amp;quot;, false, false))" 
  style="border-width:0px;"&gt;
  </code></pre>
  
  <p>Http request:</p>
  
  <pre><code>POST /edumatic3/trunk/login/accesscode/ HTTP/1.1
  Host: localhost
  Referer: http://localhost/edumatic3/trunk/login/accesscode/
  Content-Length: 1351
  Cache-Control: max-age=0
  Origin: http://localhost
  User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 
     (KHTML, like Gecko)                 Chrome/13.0.782.215 Safari/535.1
  Content-Type: application/x-www-form-urlencoded
  Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
  Accept-Encoding: gzip,deflate,sdch
  Accept-Language: nl,en-US;q=0.8,en;q=0.6,fr;q=0.4
  Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
  ASP.NET_SessionId=33yal3buv310y2etuj33qghg; CurrenUICulture=en-us
  
  __EVENTTARGET=&amp;__EVENTARGUMENT=&amp;__VIEWSTATE=%2FwEPDw...
  </code></pre>