HTTP Error 400 on Tomcat 5.0.28 and JAAS

Question

Hi
I have this problem every time I send an Authentication Request using JAAS. I've a login form and, after I send my request, LoginModule starts to process it. The problem is that, viewing the tomcat log output, the authentication goes well, but Tomcat send me a HTTP error code 400 which means "Invalid direct reference to form login page".
If I reload the login form, not back button, and retype my credentials, I reach to enter in my website. Tomcat send me a HTTP code 302, then load my home page.
This is the login HTTP message:
POST /j_security_check HTTP/1.1
Host: localhost:1999
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; it; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14
Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Language: it-it,it;q=0.8,en-us;q=0.5,en;q=0.3
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://localhost/xxxx/index
Cookie: JSESSIONID=8F91E0B617B45C1BC772E370481C8FCF
Content-Type: application/x-www-form-urlencoded
Content-Length: 65
j_username=user&j_password=pass&Submit=LoginAnd this is the login form:
<form method="post" action ="j_security_check" name="loginform" >
  <table width="100%" cellpadding="2" cellspacing="0" class="corpo">
     <tr>
      <td><div align="right">Username</div></td>
      <td width="20%"><input type="text" class="corpo" name="j_username" /></td>
    </tr>
    <tr>
      <td><div align="right">Password</div></td>
      <td width="20%"><input type="password" class="corpo" name="j_password" /></td>
    </tr>
    <tr>
      <td> </td>
      <td><div align="right">
         <input type="submit" class="bottone" name="Submit" value="Login" /><br />
           <a href="javascript:apriFinestra('<%= request.getContextPath() %>/jsp/password.jsp', '', '400px', '400px');" class="corpo"><%=lu.resource(rb, "HOME.forgot") %> </a>
      </div></td>
    </tr>
  </table>
</form>

Answer 1

There've been issues when running in the embedded OC4J server where logged messages don't appear at all - I suspect this is happening on both environments, but you're only seeing the message on Tomcat.
If you look in the HTML, you'll see a <!-- ILLEGAL HTML: --> comment where the problem occurs, and you should be able to trace that content back to the components you're using at that spot. Could you let us know what combination of components produces this error? (The problem is exactly what the error message says: HTML does not allow <img> directly inside of <table>, but that's what got produced.)