The admin script builds the new config file correctly.
The path variables echo out correctly to the config.inc.php.

It's here, that things go wrong and the file is wiped clean...
Code
$check = lock_and_write("{$config['FULL_PATH']}/includes/config.inc.php",$newconf);
if ($check == "no_write") {
	$admin->error($ubbt_lang['NO_WRITE_CONFIG']);
} // end if

 if(!defined('INSTALL')) {

	rebuild_islands(1);

} // end if

I'm wondering if there is a setting that tells ubb whether or not it has been successfully installed?