Thanks so much for your response!
The problem is that only 1 check box is visible, and therefore, only one label - either the yes, or the no, depending on which label I have put in the Display field. And this is true for my search form as well as my details form. Does that make sense? In other words, I don't see a 'yes' with a check box next to it, and a 'no' with a check box next to it.
In the 'configure search fields, I have selected:
Form Element: Radio Buttons
Comparison type: Equal
Field Options Placement: Multiple options per line
Display: Yes
Value: I left blank
Than