Has anyone dealt with or have information about why the PA individual tax form REV-1630 (Underpayment of Estimated Tax) does not calculate correctly.

For certain taxpayers whose income is taxable income fluctuates during the year, we complete in screen (8) in the section : Pennsylvania Annualized Income Installment Method, the taxable income per 1q, 2q & 3q. 

Form REV-1630 is recalculated based on this but in Section II - Exceptions To Interest, Line 12 - Exception 1 Worksheet shows the total for each quarter does NOT fit the criteria for under Exception 1 for that quarter period to be exempt from the interest assessment but on the supplemental 'Underpayment Penalty Worksheet' it does record it as if Exception 1 applies. As such the true amount of the assessment is not recorded on the final tax return. 

If we remove the info in in screen (8) in the section : Pennsylvania Annualized Income Installment Method - the software does calculate and record the correct interest assessment. 

Recently, we are receiving notices from the State billing for the true assessment due.