apache 2.2 - Can't configure PHP error log

I'm running apache2 with php5 on Linux Mint 13 Maya. I have defined a virtual host and these two entries there:

ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined

That produces error and access logs in var/log/apache2.

I want to make my PHP errors go in PHP error log. In my /etc/php5/apache2/php.ini I have set:

display_errors = On
log_errors = On
error_log = /var/log/php-errors.log
log_errors_max_len = 0
error_reporting =  E_ALL | E_STRICT

The log file /var/log/php-errors.log

got generated, but all it logged was two warnings that some modules were already loaded. I tried to comment out the log directives in virtual host defintion but that changed nothing, all the errors are still logged in apache log.

What am I missing here?