Indeed there are a few reasons this may happen.
First, simply excluding a topic or a book in the TOC simply makes sure that the TOC doesn't have a link pointing to the topic. Normally, I'll just tag the topic itself and ignore tagging the TOC. If a topic has been excluded, it won't appear in the TOC.
In the WebHelp SSL recipe, click to expand the Content Categories section and look at the settings on the right. You might try ensuring the following option is enabled. It's named Exclude Unreferenced Topics from Output. As long as nothing else is linking to the topic, ensuring it is removed from the TOC *SHOULD* cause it to no longer be included.
Thanks Rick! I will try this. With my deadline a week away, this was not a good time to stumble upon this problem, but at least I didn't find it after the product was released.
well, unfortunately, I tried both options you suggested and neither worked - the content still shows up in search.
I selected the Exclude Unreferenced Topics from Output check box in the Content categories section when generating. I applied the build tag directly to the topic.
I welcome any other suggestions.