Here's what I use the Kirby came up with and it works excellently by the way.
Also, you don't need an if THIS_SCRIPT with it doing it this way. It works globablly. I have one for forumdisplay and 2 for forumhome in there and they all work fine.
PHP Code:
// ****** SPECIALTEMPLATES *****
// Add any specialtemplates here for any products or mods that use the datastore, to save
// from re-doing file edits on an upgrade or re-install of vBulletin (until they give us a better
// way to do it, anyway). Thanks to KirbyDE for the how-to on doing this.
global $specialtemplates;
$specialtemplates = array_merge(
$specialtemplates, array(
'forumstatscache',
));
I added the little description to make it look more uniformly.