secure a website - a turk keep hacking my root

Hi, I have a videowebsite - a copy of youtube - but it keep getting hacked by a turk - [login to view URL] - I can see all the files in the FTP directory - however even if i type [login to view URL] - it still shows the hacked page - [login to view URL] still show the right page, but login dosent work. i've tried to find the database but it seems like it is gone.. When i " restore " the domain from Cpanel (plesk, linux) it removes the hacked page from [login to view URL] - but shows a page saying something like: youre using fedora cora plesk.... if you can see this page, it means it works.... I have all backups of the website (database etc. ) but I need it secured from the hacker - and its a dedicated server. if any help: I keep getting security notes by mail from the server saying: This letter was generated by security scanner started on host [login to view URL] at Aug 20, 2007 01:00 [login to view URL] inspect this machine because there can be security problems or holesin its protection, or the machine can be infected. Security scanning generated the following warnings (the full scanning logis available at /var/log/[login to view URL]): [01:00:52] WARNING, found: /dev/.udevdb (directory) /etc/.java (directory) [01:00:53] Warning: root login possible. Change for your safety the 'PermitRootLogin' thanks alot