Cannot login in acp via portal

[MatMat]

Your Portal Version: 1.0.5
Your phpBB Type: Standard phpBB3
MODs installed: Yes
Your knowledge: Beginner
Boardlink: http://www.domotica-opensource.com

PHP Version: 5
MySQL Version: 5

What have you done before the problem was there?
I read, i think, all the related posts of the forum, but unfortunely without success.
I unistalled and reisnstalled many times the portal, with no success.

What have you already tryed to solve the problem?
I tryed to look the php code... with no success

Description and Message
I m sorry for my poor english. I try to be more clear i can.
I made portal installation, in all parts with success. I had the result messages, that it was all ok.
When i link to www.domain.xx/forum/portal.php i go to the page of the portal. It s all perfectly working!!
but when i try to log in the login box on the right of the panel, my browser(IE,FireFox,Chrome) go to a link(/portal.php?&sid="idcode" ).
I tryed to confront the "idcode" in login via portal and "idcode" in login via forum(phpBB). They re not equal.
When i login via forum, i go to my admin panel and i can work well. When i login via portal, browser go to a white page (portal.php?&sid="idcode" )
I putted all the files in correct position, and followed the install.xml at the letter.
Where i made mistake!!!!!!! I can't undestand.

Any help is appreciate.
Thanks very much.

Mat

[MatMat]

I'd like give some other information. Maybe it could be usefull.
Looking at user session id, i can see that when i make login via portal login box, the user session id is different from the user session id i have when i make login via forum login box.

Thanks
Matteo

[MatMat]

Hi ,
i read the topic about the php tag, that can cause this problem. I looked in many php pages, but not found problem in the php tags.
What php files i should look. I looked: portal.php, functions.php, ucp.php, common.php, constants.php

Thanks
Mat