The tax reported on 1040 Ln 16 does not with IRS Pub 17 Tax Tables.

The tax due calculated by the program and reported on 1040 Ln16, is about 1/2 the amount in the IRS tax tables in Pub 17 for the amount of taxable income the program reports  on 1040 ln 15.  I couldn't find anything to explain how the program arrives at the tax amount it reports. 

I am using Premier loaded from a CD.  I check for updates each time I open the program.