jadijk, the phpnuke integration is out of date, but maybe it still works with the correct params:
<?
$g2embedparams = array (
'embedphpfile' => '/var/www/html/gallery2',
'embedUri' => 'modules.php?name=gallery2',
'embedPath' => '',
'relativeG2Path' => 'g2data/',
'loginRedirect' => 'modules.php?name=Your_Account',
'activeUserId' => '0',
);
$g2mainparams = array (
'showSidebar' => NULL,
);
$g2configurationdone = "true"?>
and if that doesn't work, try 'embedphpfile' => '/var/www/html/gallery2/embed.php',