After you file

I started an amendment for a return where I was receiving a refund back from both federal and state.  IRS and state "accepted" my returns.  I started my amendment and my state "counter" went to zero but my federal went way into negative territory.  I continued on and entered additional 1099-DIV income that I'd forgotten.  The state now shows I owe (checked it all - looks okay) but federal still shows big negative number.  I went through it with a fine tooth comb and all the calculations appear correct EXCEPT I see that line 16 on the 1040X shows that I paid several thousand dollars with my return (I did not -- I'm still waiting for my refund).  I have not made any EFTPS payments either.  Where is Line 16 getting the number from?  I am tempted to override this with a zero --- wondering if there is an error?  Thank you!