Problem bridging Coppermine 1.4.8 & PhpBB 2.0.21

[pukas]

I have the following issue when trying to bridge coppermine and phpBB 2.0.21:
No error, but when I try to login or logout, I see a page not found, but if I recharge the page, my action have succes, so I'm logged in or logged out as I want...

Coppermine install: http://fantagalla.altervista.org/home/fotogallery
Forum install: http://fantagalla.altervista.org/home/forum
Coppermine version: cpg1.4.9
Forum version: phpBB 2.0.21


BridgeManager settings:
Forum URL:  http://fantagalla.altervista.org/home/forum
Relative path to your BBS's config file:  ../forum/
Use post-based groups?:  0

any help would be appreciated.