In a setup where we use Apache FastCGI with PHP through mod_fcgid and suEXEC, we experienced the problem that long running scripts always resulted in a 500 Internal Server Error after exactly 40 seconds. This is due to the IPCCommTimeout setting, but changing that setting didn't seem to yield any effect.
I stumbled on a blog entry saying that they only work within the VirtualHost block. I tried this for my test-vhost but it also didn't work. It took me a while to find the complete solution (workaround): you need to specify IPCCommTimeout in every VirtualHost block, because a later VirtualHost will globally reset your setting in a previous one.
So until this bug is fixed the neat workaround is to place the mod_fcgid settings in a separate configuration file and Include that file inside each VirtualHost.
