I'm delighted to let you all know that I found the answer!
Having even gone as far as looking through the apache source tree and examining log.c (which didn't really get me anywhere) I did a load more searching on the net for this one.
Everything was pointing to an SELinux problem, but "No" I thought, it can't be - I've disabled it.
Having followed the instructions for disabling SELinux in this howto
, I concluded it was indeed disabled. However, my sysadmin instinct told me otherwise, so I did a bit of poking round Fedora.
I found a file called /etc/sysconfig/selinux
On editing it, I found that the system-config-securitylevel-tui had been lying to me! Although this had worked perfectly on another server, selinux was showing as "enforcing". So, I changed the file to read as follows:
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - SELinux is fully disabled.
# SELINUXTYPE= type of policy in use. Possible values are:
# targeted - Only targeted network daemons are protected.
# strict - Full SELinux protection.
# SETLOCALDEFS= Check local definition changes
I then rebooted the server for good measure, and up pops apache happy as anything.
I guess it might be worth updating the howto to reflect this too...
Just hope that helps someone else. I'll try and backlink this from the other depressed postings I made !!
Thanks for all your help and support so far,