Now this is strange...
I'm using PP2014 SR 3.2, since you asked, and that "Show Hidden Parameters" option worked in all SRs. Funny.
I know that I might sound like a SM "Customer Support" dud right now, who always tells you the standard reply:
"uninstall/reinstall Poser"...
But sometimes it's the only way if Poser screwed up.

I had a funny issue when in the "Render Settings" box all the buttons below (OK, ABORT, etc.) were gone, nada, nichego.
They returned only after a fresh intall of Poser. Doh!

Peter