[Zope] Session and IE problem

I've build a site that uses sessions. The setting is: 1) a web redirection to our ip: www.asite.com -> 123.45.67.89:8080 2) apache redirects with mod_rewrite to Zope 3) Zope is called with 123.45.67.89:8080/Store and sends 123.45.67.89:80 back 4) the user has to log in and the session is created Except of IE (I test it with version 6) all the browsers are working fine. When I call 123.45.67.89:8080 directly also IE is working.. What can I do? I've just searched for hours the archive...