I could not get this block working either but i found the reason.
I moved the portal.php outside the forums directory and then the $config['script_path'] makes the path to the ventrilo_status.php wrong so i replaced that with $phpbb_root_path and then got it working so here is how you make it work ...

Thank you Kevin

This is the one i would like to download
viewtopic.php?f=38&t=1899

Your Portal Version: 1.0.0RC3
Your phpBB Type: Standard phpBB3
MODs installed: No
Your knowledge: Beginner

PHP Version: 5
MySQL Version: 5

What have you done before the problem was there?
The problem is at your site

What have you already tryed to solve the problem?
The problem is at ...