Hmm... well, as the PRC is basically run by a bunch of hak files (and a tlk file, plus some portraits...) and shouldn't, in theory, be overriding anything at all, you could try the
NWN patch page and install the critical rebuild for 1.69 in whichever OS you're using. It's a long download, but it's also basically everything except .ini files, your key file, and such.