Found the problem! The phantom business was hiding out in the wizard for a Farm Rental that generates form 4835. Man, stuff can get buried in the wizards! You have to have the right checkbox selected at the beginning of Farm Income and Farm Rental section (the checkbox called "I received agricultural payments on a 1099-MISC or 1099-G for my farm rental"). I had started down that path early on and decided that I needed to enter this Farm Rental as a Schedule E instead, so that business with no data in it was still lurking behind that other path in the wizard! I hope this helps others track down a phantom Farm Rental business if a similar situation occurs.
