Trouble with Form 1041 Schedule G tax calculation?

[mrpjvt]

TurboTax Business calculated no tax due on a complex trust with Ordinary and Qualified Dividends.  IRS has just notified me that they believe tax is due at a 15% rate as per Schedule G.  I'm not able to use the Qualified Dividends Tax Worksheet because short and long term gains were reported in Sched. D Parts I & II.  That Worksheet would have calculated no tax due.  TurboTax found no errors when running reviews and error checks and still says no tax is due.  Why?