@SteamTrain Thanks for your careful answer.
Mystery solved. I did use the interview to enter the form data, but when I ran the review, TurboTax flagged an error and directed me to the form. There, under the state withholding data -- which, as you say, TurboTax "moved around" (which is what threw me) -- was a little box asking for verification that the state withholding amount is correct. TTAX wanted that checked. I checked it, and the error disappeared. Now to sort out why TurboTax doesn't like the multiple-business K-1 I'm trying to enter...
