What third party are you using I use WinRAR on PC and its fine & just tried My MacPro with Maverick 10.9.1
All Clear there, it automatically unzip for me on the Mac in my download folder.
I used izip Stuffit Expander. I have 10.9.2 as well. When I click to open the zip a duplicate .cpgz file pops up.
There're other files in the download with the zip file so it may have unzipped automatically but I don't know the exact contents in the zip so I have nothing to compare it to.
Here's what I have:

This may be the contents I need to upload to my card but I don't know. If anyone has any suggestions please let me know. I just don't want to risk turning my camera into a brick.
Thanks!