Serious Error for Reporting Gain on Home Sale when Married Filing Separately

In IRS Publication 523, it states "If single or married filing separately, figure gain or loss as an individual." And, "If the home you sold had multiple owners, your gain or loss is the gain or loss on the entire sale multiplied by your percentage of ownership".

 

But TurboTax Premier doesn't do this. I'm working on my return for Married Filing Separately, and the step-by-step procedure doesn't even ask if  I shared ownership with my spouse, attributing 100% of the gain to me. This is even though drilling down into forms shows the worksheet with checkbox's for "Owner of home is: Taxpayer, Spouse, or Joint". I tried overriding the Gain on Sale (line 7) , dividing the amount the program calculates in half, but it makes no difference in the amount of taxes Turbotax says I owe. 

 

There are other questions and checkboxes in the worksheet section titled "Qualifying For and Electing the Exclusion for Sale of Your Main Home", and the software doesn't ask those questions either.  Once again, checking the boxes manually makes no difference in TurboTax's calculations. 

 

Help!!!