PHP 4 in remapped subdirectories?

For some reason, PHP scripts in a remapped directory are executed using PHP as an Apache module, version 4.4.2, instead of PHP 5.1.6 running as a CGI module.

Comparing these two phpinfo() pages:

Both domains/subdomains are configured to use PHP 5.1.6. The first page, however, is inside a remapped directory (/w/). The phpinfo() data shows that it uses version 4.4.2.

Is there any way to change this? Since the directory is supposed to host a MediaWiki site, it requires PHP5…

Edit: And yes, there is a reason the directory is remapped; the rest of the domain is in the Drupal directory my other sites use, which I’d rather not clutter up with the MediaWiki software. I suppose I could find alternative ways of doing this, but I’d rather try it this way first.

Edit2: Links currently don’t work; the server is down. Don’t blame me. <_<

Not to press the point or anything, but I’m still trying to find a solution for this one…