Apache ErrorLog

I was wondering where CPanel gets the Error Logs from, so I checked httpd.conf manually and just found a single ErrorLog directive.

On this server here apache's error log is written to /var/log/httpd-error.log for ALL virtual hosts and I am trying to figure out where CPanel gets the information for every single VHost which is being displayed in Statistics -> Error Logs. Is this information being extracted from /var/log/httpd-error.log ?

We are having all sorts of problems with this feature. On one server the error logs won't be displayed, on another they are always delayed by 6 hours (they get refreshed, but are 6 hrs behind). I'm trying to pinpoint the problem's cause, but I haven't got the faintest idea where I should start looking.