SSO to Web App using Application Integrator - not working (SP15)

Question

Hi,
I have created a web app system and generic app integrator iview for my web application (and set up user mapping etc.), following the Application Integrator how-to guide but it does not log me into my web application. I have got the Yahoo example working, and if I use a HTTP System & URL iview for my web application, that also works. Can anyone tell me what the problem could be, or where I should start looking?
If I use a http sniffer, I can see the correct URL and parameters in the following:
function requestTargetURL() {
      var theURL = "<b>HTTPS://(myserver)/log-in.htm?op=(####)&pwd=(####)</b>";
      var dsmObj;
      if (hasNestedFrameStructure()) {
        location.replace(theURL);
        dsmObj = parent.EPCM.DSM;
      } else {
        document.body.scroll = "no"; // for IE only
        var theIframe = document.getElementById("iframe_GETRedirect_592312569");
        theIframe.style.visibility = "visible";
        theIframe.src = theURL;
        dsmObj = EPCM.DSM;
        document.title = 'JDS';
    function onloadhandler(){
      setTimeout("requestTargetURL()",1);
but something else must be happening for it not to work. Can anyone give me any pointers?
Many thanks
Jane

Answer 1

Bit of a weird one: I've found a way to make it work but I'm not sure exactly how... the problem was that the portal was opening my web app URL in an iFrame (which can be seen from the code above). I tested this by just creating a html page with the URL + parameters in an iframe, and it wouldn't log me in (and took over the whole browser). So I guess the problem is with my web app rather than the portal.
However... I then discovered that if I add my web app address to the Local Intranet security zone in my browser (IE6) settings (before it was in the Trusted Sites zone), it no longer minded being in an iFrame, my test html page worked and so does the portal iview. I cannot find which security setting is causing this - I've tried changing the Trusted Sites to match the Intranet zone settings exactly, but it still doesn't work if my web app address is Trusted opposed to Intranet.
If anyone has any idea what is causing this behaviour, I'd be very grateful - obviously it isn't a portal issue but I'd still like to find out the cause in case it comes up again in the future.
Many thanks,
Jane