Hello
I found and resolved the problem:
I work with the new release 3.2 but not from the install CD of Zentyal.
So i install ubunt server 12.04
Install lxde
install firefox
install zentyal office and zentyal infrastructure.
If installing firefox only by the command:
apt-get install firefox the firefox browser works but there is a problem with showing trac.zentya.org the browser endless try to connect and the trac page is never showed.
To solve this problem firefox must be installed in an other way with the next commands
note you must be root to do this
sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
sudo apt-get update
sudo apt-get install firefox
So afther executing this commands, firefox works properly and the page trac.zentya.org is showed now.
Best regards,
Ian