How can I uncheck "Binary Index" if I have already disabled all keywords?

A week or so ago, I asked a question about the binary index and how to delete topic keywords so I could uncheck the box on the "Project Settings" page.  I received a great, helpful response: "

First, click View > Pods > Project Manager.

Locate the Index folder and expand it.

Double-click the Index entry in the folder to open the Index Designer.

Scan the topics listed in the top part of the Index Designer. You are looking for any topic that has a Page icon with a Key superimposed."

So I did all of this, and it worked great for all of my projects but one.  I have deleted all of the keywords, but I still am unable to uncheck the box.  Anything else anyone can suggest that I do?  Anywhere else I should be looking, or something I may be missing?

Thanks!