Hello,
First, thank for your extension, it works very well. 
I use Joomla 3.4 and phpbb 3.4, both forked with P8Pbb Bridge.
The forum is also encapsuled in the Joomla template.
I installed freichat with phpbb integration (to have users avatars displaying correctly because I have no avatar system on Joomla), and I put the given code in overall_header.html as mentionned during the installation.
It works fine, my users are displayed correctly, and also the phpbb avatars.
But freichat is only displaying on forum pages, not on Joomla pages.
I try to put the given code in index.php of my joomla template rather than in overall_header.html, but it don't work.
Is there a possibility to display the chat module in all my website pages (Joomla and phpbb) by changing something in the code ?
The code is the following :
if(!function_exists("freichatx_get_hash")){
function freichatx_get_hash(){
global $user;
$ses = $user->session_id;
if(is_file("/home/xxx/www/freichat/hardcode.php")){
require "/home/xxx/www/freichat/hardcode.php";
$temp_id = $ses . $uid;
return md5($temp_id);
}
else
{
echo "<script>alert('module freichatx says: hardcode.php file not
found!');</script>";
}
return 0;
}
}
<script type="text/javascript" language="javascipt"
src="http://www.xxx.fr/freichat/client/main.php?id={SESSION_ID}&xhash=<!-- PHP --> echo freichatx_get_hash(); <!-- ENDPHP -->">
</script><link rel="stylesheet" href="http://www.xxx.fr/freichat/client/jquery/freichat_themes/freichatcss.php" type="text/css">
I tried to install Freichat with Joomla integration, but the random avatars displayed are not those of phpbb, so I have choose phpbb integration instead. 
Thank for your help.
Bye.