I completed a Form 1041 for a client and did not mark "final return". Upon filing the return I realized my error and marked the box. I didn't realize the $600 exemption had been eliminated by making that change on the tax return until the IRS tax payment was higher than expected. I don't see in the publication or instructions that the exemption is eliminated upon filing a "final" Form 1040 for an estate. Is this a glitch in the program???