Text found via search stays highlighted perpetually

Does anyone know how to fix this annoying problem in Flash Builder 4.7?

1. Click Search > Search (or press Ctrl+H).
2. On the 'File Search' tab, enter some text that you know will be found.
3. Click 'Search'.
4. In the 'Search' view, double-click one of the results so its file opens in the editor.
   
   At this point, the text found via the search is highlighted (purple by default), which is what you want.
   
   
5. Now close the 'Search' view.

Result: The text found via the search remains highlighted (and everywhere else in the project), which is not what you want.

It didn't used to be this way for me. When I closed the 'Search' view in the past, all the highlighted terms became unhighlighted. (Note that my 'Mark Occurrences' button is not toggled.) Is there some obscure option somewhere to keep text highlighted after the 'Search' view has been closed? (I certainly didn't enable such a feature, but if it exists I'd love to disable it.)

Thanks,

Rob