It's not you, Kait. I also tried changing the setting in my preferences, and it is stuck on 'Yes' (meaning I can't disable the auto install option).
In any event, you don't need to use the Auto Install feature to get this installed. Just use the Download Zip File button on the download page, which should prompt you to to do one of three things....Run, Save, or Cancel. I normally just Run stuff from this kind of prompt (it will, of course, need to download the file first
), as this saves you from that annoying step of deleting the file once the installation is done. Once you get the installation going, it's pretty straight forward. Just follow Faetyl's instructions (linked in my original post above) and you should be set in no time.