Originally Posted by till
The file is ok. The messages "Connection reset by peer: mod_fcgid" are logged when someone e.g. presses the cancel button in its browser while the page loads or when the connection is interrupted. So there is no problem on your server.
Actually this happened frequently to a lot of Firefox users, regardless if anyone was hitting Cancel or not.
According to the serverlogs, fcgid was hitting its end of life and getting restarted. Everytime that happened while a user was loading a page, they would get an error message in Firefox, or IE8 would drop into "compatibility mode". This happened multiple times a day to multiple users (including myself) at very random times. It was a very frequently-reported bug.
Uncommenting these two lines:
# export PHP_FCGI_CHILDREN
and reloading the web server has finally fixed the problem. Now there's a running fcgid process waiting when an old one reaches EOL and gets shut own.
I needed to do this on every vhost, because each one suffered the same fate until that change was made.