I'm still running into an issue on Win8 64bit. When I do the simple install, it tells me that there was an issue, and leaves it at that. If I open up the security catalog file, it tells me the signature is invalid. Advanced driver install (going into manage devices, and install driver from disk) tells me that I have an invalid security hash.
I'm using the latest version of the add-ons zip, v06.
EDIT: Tried again with v05, just in case. Still no dice. I'll try disabling Win8 signing tomorrow.