dont know if i posted it already...but if someone from isp / serveradmin could change the debug information about the php in php.ini then the warnings from the forum are gone
like:
Warning: Cannot modify header information - headers already sent by (output started at /usr/local/www/www.unrealadmin.org/public_html/header.php:32) in /usr/local/www/www.unrealadmin.org/public_html/includes