Are you talking about the screen with the title, "Any Periodic Payments"?
Yes, that screen resets your answer to "No" each time you enter that screen.
Don't be concerned - if you entered Yes before, it is still Yes...until you go through the 1099-R interview again and re-enter this screen.
If you travel throughout TurboTax, you will see a few screens that do this - appear to change your answer. These screens do this because the answer is so important (i.e., changes the flow of the program), that TurboTax wants you to reconfirm your answer each time.
Don't worry, your Yes answer is safe - just be sure to remember to change the answer to Yes each time your re-enter this screen.