When I open a url with a non-existent php file on my site, for example :
it logs a 404 error into the apache error log, but it doesn't show the requested url, it just shows :
File does not exist: /path/to/public_html/404.shtml
If I request a url with a non-existent html, jpg, etc, the log entry displays the file.
I looked in httpd.conf and there are no CustomLog entries.