Pre-tax deductions are not getting deducted from Negative taxable amount in US payroll

Hi Experts,

When a negative amount entered for 12FN(Forg Notes – Prin non-cash) wagetype on infotype 14 for the date range 01/01/2013 – 12/31/2013, and the employee is set up to retro back to 01/01/2013, the system is incorrectly calculating taxable wages for all tax authorities. The taxable wages are overstated by the total pre-tax deductions in the current period. Pre-tax deductions are not getting deducted from the negative taxable wages. When we run the payroll for an employee in US(Semi-monthly) for Period 15, this employee should have -1,724.53 in Federal, New York, and New York City taxable wages but the system is calculating -$1,005.40. Pre-tax deductions 719.13 are not getting deducted from -1,005.40$.

Could you please let us know how this issue can be corrected.

Thanks,

Santosh