The answer to this is get the Mark Lineage Package from entropy.sh.
Do not get me wrong the entropy packages are really very good and without them over the years we would all have had a lot of pain. Their quality can however lead to a false sense of security and I mention this as a word of caution.
Do make a backup of your HTTPD folder before doing an install or upgrade. I did an upgrade from 5.0.4 to 5.1.4 and it broke apache. The package was expanded using tar -xvf. and php 4 was not running but the installer did not complete and errored out, logs showed
[code]2006-07-29 17:10:20.592 Installer[12323] Exception raised during posting of notification. Ignored. exception: The postflight script in entropy-php failed. (code 6)[/code]
At this point nothing untoward was noticed, until restarting apache that is, which then failed. I restored my httpd.conf and things got slightly worse because not only would httpd not restart but server admin did not recognise any of the sites. Running apachectl restart and a combination of viewing errors and error logs pointed out the culprit. /etc/httpd/sites/+entropy-php.cnf. When the entropy installer errored out left this file behind. Removing it or mv it to backup_+entropy-php.cnf.bac allowed httpd to restart. At this point I re installed an earlier version of php, ‘entropy php.5.0.4’ and while not having 5.1.4 at least I had a working server.

To summarise, backup /etc/httpd and /usr/local/pph5 before upgrading, that way you can rollback to a working configuration if anything goes wrong.

I will attempt an install of entropy php 5.1.4 on a test server running 10.3.9 and report back on any problems and or work arounds.