I tried searching but couldn't find anything. Two guesses:

1) scour elsewhere in your return for fed/state differences. Test taking them out to identify the diagnostic trigger item, and then see if you can get that same input on the forms through another input field.

2) try pressing CTRL+W to go into batch entry mode and see if there's a ghost item code on Screen 51.371 (or elsewhere) that you can hit CTRL+D on to make go away. Maybe that will clear it. That worked for me on Screen 48 "Summary" recently where I had a blank input screen for new clients but was getting an ugly PY column of zeros on my Tax Summary Report in Forms.

Good luck!