Seems like I can't get error logging working on my server, I've set up my vhosts like in this description like suggested here.
<VirtualHost *:80>
ServerAdmin admin@server.com
DocumentRoot /var/www/html
ServerName www.server.com
ServerAlias server.com
LogFormat combined
ErrorLog /var/log/apache2/server.com-error_log
TransferLog /var/log/apache2/server.com-access_log
php_flag log_errors on
php_flag display_errors off
php_value error_reporting 6143
php_value error_log /var/log/apache2/server.com-php-error.log
...
</VirtualHost>
access and error log are written correctly, the php error log file is created and has the same permission as the other two log files.
I also tried to set the logging in the php.ini, .htaccess file and in the script, all according to this guide.
php -v
PHP 5.2.10-2ubuntu6.10 with Suhosin-Patch 0.9.7 (cli) (built: May 2 2011 23:24:44)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies
Are there any other places I could check? The vHost configuration worked flawlessly on other servers.