(This actually applies to PHP 4.1.2, but the pulldown box on the bug reporting page hasn't been updated to reflect that yet).

When Apache (1.3.23) is compiled with mod_ssl (2.8.7) as a DSO module, mod_ssl automatically adds this to httpd.conf:
...
<IfDefine SSL>
LoadModule ssl_module         libexec/libssl.so
</IfDefine>

Later, when building a DSO version of PHP (4.1.2), using the --with-apxs option, PHP helpfully tries to add the appropriate LoadModule/AddModule directives to httpd.conf.  However, it appears to guess incorrectly where the LoadModule directive should go, so httpd.conf now contains this:
...
<IfDefine SSL>
LoadModule ssl_module         libexec/libssl.so
LoadModule php4_module        libexec/libphp4.so
</IfDefine>

which will cause PHP not to load (and httpd to not start) unless SSL is also running.

The solution, of course, is for httpd.conf to look like this:
<IfDefine SSL>
LoadModule ssl_module         libexec/libssl.so
</IfDefine>
LoadModule php4_module        libexec/libphp4.so

(actually, as I dig into the PHP code, I'm beginning to wonder if it's an apxs problem rather than a PHP problem.  Still, even if it is, perhaps PHP's installer can work around it?)

Thanks.