Comment 5 for bug 44975

I've looked over the documentation for Apache and may have found the reason why you're having problems. It *is* indeed possible to define multiple log files, so it's not because your deflate.log gets overridden later, *but* http://httpd.apache.org/docs/2.0/logs.html#virtualhost says that "If CustomLog or ErrorLog directives are placed inside a <VirtualHost> section, all requests or errors for that virtual host will be logged only to the specified file. Any virtual host which does not have logging directives will still have its requests sent to the main server logs."

Does that perhaps apply to your setup?