The issue has been resolved. The following directive worked (for PHP 5.2.5 on Apache 2.2.8):

SetHandler application/x-httpd-php5

In my previous post I reported that I had installed the script on a second host and had problems there, too. The first response to my support ticket on the second host was that the script wasn't even installed. I guess they took a quick glance and saw there was no directory called /links/directory and went no further. After I pointed out to them that it was, indeed, installed and that the admin section was working fine, they figured it out. And presto, the addition of the number 5 solved the problem.

My main concern with this is that it might mean my links site will stop functioning if and when there is an upgrade to php6.

Hrm... I haven't seen that one yet. Adding it to the FAQ. It's odd, but I suppose it could be kind of handy to be able to specify which version you wanted to use. .. and yes, likely the next time there is a major PHP upgrade, I suspect it will stop working again. Of course if they used the standard application/x-httpd-php .. to maintain backwards compatability ... well, one can hope.

Hi guys,

Thanks for for sharing this on the forum.
I had exactly the same problem and this also solved it for me.

My .htaccess file only contained ForceType application/x-httpd-php
Adding a 5 to the end of that line did not work but adding your suggested line SetHandler application/x-httpd-php5 did the job.
PHP 5.2.5
Apache 1.3.41

I've only just registered on this new forum but I always had great support via the old forum during my PHPlinks development phase
http://www.chilternphoto.org.uk/introduction/photogroup/search/index.htm

Thanks again to both of you.