APEX

I've been trying to set up NTLM authentication for APEX as described on [this blog|http://jastraub.blogspot.com/2008/03/ntlm-http-authentication-and.html] and in [this whitepaper|http://www.oracle.com/technology/products/database/application_express/pdf/apex_ntlm_authentication_wp.pdf].

The enviroment is as follows:
DB: 10.1.0.4.2 on a windows 2003 SP2 server
Application server: 10.1.2.3.0 on a windows 2003 SP2 server
Clients: windows XP SP2 / IE 6 & 7 (tested both)

The authentication appears to work fine, but it does seem rather slow (~20 seconds).

I've tried using the earlier version of the page sentry function (without the hacky bits to trick IE) and this works pretty much instantly in Firefox (but gives the expectected problems in IE).
I've experimented with commenting various bits out to find out which bit might be causing the issue, and it apears to be when the session cookie is being re-written into the HTTP header
ie:
>
FOR ii IN 1 .. l_htp_rows LOOP
IF l_htp_buffer(ii) LIKE 'Set-Cookie:%' THEN
htp.p(l_htp_buffer(ii));
END IF;
END LOOP;
>
I've been trying to analyze the HTTP traffic, but it just appears that there is a 15-20 second delay before recieving a reponse from the server.
I've tried logging the steps int he function into a table, and it all seems to happen pretty much instantly, so I guess the issue seems to be occuring on the Apache server?

Does anyone have any ideas what might be causing this, or any further steps I could take to diagnose?

Thanks,

Keith