HTML5 Output Bringing in Strange Headers

I'm taking my first, cautious steps into the world of Responsive HTML5.

The default output actually looks pretty good.

The problem is that it seems to be bringing in some weird, unrelated headers from somewhere that appears to be buried deep in the output template FM files.

Example:

Below, I searched for "control" and got a result:

The weirdness is that title "Preventing Vehicle Rollover". Nowhere in the book that I used to generate this output is that title used. We have used that title before, in other documentation, but not here--it's not in the XML or the map files used to create the book.

Out of curiosity, I opened the chapter output templates in Notepad++, and I found the title in a few different places, like this:

and this:

At one point, I tried using a "clean" chapter output template and the search titles came out as "Safety":

Where are these bad titles coming from, and how do I get my HTML5 output to use the correct titles; those being "153 - Hydraulics - etc."?