Have you checked on the plug-in’s creator’s website?
Edit: Maybe check out Mr.Cox’ posts in this thread.
I have. But, to be honest, their website is so confusing I couldn't find much useful information. KPT is, apparently, no longer a stand-alone filter set. They now are part of Paintshop, and the most up-to-date versions of Paintshop aren't out for Macs, let alone Mountain Lion 10.8.
I'm hoping to hear from fellow Mac users who are currently using KPT in PhotoShop CS6 to see what versions they have installed so I can update my KPT set.