You need to chmod the /home/groups/u/up/upp/htdocs/FUD2/install.php file 666 (-rw-rw-rw-), so that the installer can modify itself. This is needed to avoid problems since your PHP installation enforces memory limit setting.
This step applies ONLY to users who's PHP has a memory limit. Make sure that the directory the install script is in is either writable by the webserver or that a "fudforum_archive" file exists and is writable by the webserver. The latter applies only to users on servers WITHOUT safe_mode.