Error 500

[theprincy]

please help me ...
I really do not understand how to remedy 500 error

/var/log/apache2/xxxxxxx-combined.log

84.222.191.254 - - [26/Aug/2009:17:28:08 +0200] "GET /client/mail_edit.php?id=223 HTTP/1.1" 200 2921 "http://151.1.153.22/client/mail_accounts.php" "Mozilla/5.0 (X11; U; Linux i686; it; rv:1.9.1.2) Gecko/20090730 SUSE/3.5.2-2.1 Firefox/3.5.2"
84.222.191.254 - - [26/Aug/2009:17:28:09 +0200] "GET /themes/omega_original/images/content/table_icon_doc.png HTTP/1.1" 200 1707 "http://151.1.153.22/client/mail_edit.php?id=223" "Mozilla/5.0 (X11; U; Linux i686; it; rv:1.9.1.2) Gecko/20090730 SUSE/3.5.2-2.1 Firefox/3.5.2"
84.222.191.254 - - [26/Aug/2009:17:28:09 +0200] "GET /themes/omega_original/images/content/table_icon_doc.png HTTP/1.1" 200 1707 "http://151.1.153.22/client/mail_edit.php?id=223" "Mozilla/5.0 (X11; U; Linux i686; it; rv:1.9.1.2) Gecko/20090730 SUSE/3.5.2-2.1 Firefox/3.5.2"
84.222.191.254 - - [26/Aug/2009:17:28:09 +0200] "GET /themes/omega_original/images/icons/help.png HTTP/1.1" 200 3567 "http://151.1.153.22/client/mail_edit.php?id=223" "Mozilla/5.0 (X11; U; Linux i686; it; rv:1.9.1.2) Gecko/20090730 SUSE/3.5.2-2.1 Firefox/3.5.2"
84.222.191.254 - - [26/Aug/2009:17:28:09 +0200] "GET /themes/omega_original/images/icons/help.png HTTP/1.1" 200 3567 "http://151.1.153.22/client/mail_edit.php?id=223" "Mozilla/5.0 (X11; U; Linux i686; it; rv:1.9.1.2) Gecko/20090730 SUSE/3.5.2-2.1 Firefox/3.5.2"