[Typo3] Login for Frontend users not working (PHP 5.0.5, Windows 2003 server and IIS)

[Jan Bidner]

Hi list,

This is my second try with this question. Hope to have better luck this
time...

Is there anyone who has experienced any problems with the login-extension
(Front-end-users) with the following configuration. I would very much like
to no what's causing it. Could it be the PHP-version?

-----------------------------------
 
I'm managing a medium-scale website with intranet for a swedish
university-consortium (www.ladok.se). Until lately it has been hosted on a
webhotel on a Linux-machine with an apache server, mySQL (klient api version
3.23.52) and php  (version 4.3.4). Typo3 version was 3.6.
 
After the move (to a dedicated server) the site is hosted on a Windows 2003
server with IIS (due to plans of co-hosting another application) , php
(Version 5.0.5) and mySQL (klient api version  4.1.14). Typo3-version was
upgraded to version 3.8. Everything seems to work just fine (enhanced speed
and great performance) except for one major bug:
 
Front-end login is not possible!!!
 
I wonder what might be the problem. Backend-login works and all kinds of
administration, submitting news etc. I have been going over the php.ini file
for possible problems but I just can't figure it out. The old installation
hade safe_mode set to On. But that was ok then, even though it might have
slowed the application down. Now it's set to Off to increase performance.
 
Anyone experienced anything like it? What makes the front-end login not
possible? (Tried both newlogin and the simple). Both works just fine in the
old setup but in this conifguration: NADA!!!
 
- Grateful for any kind of answer
 
/Jan Bidner