Calculating a tax credit is a lot more complicated than having a simple additional tax deduction. Possibly, TaxCut just isn't equipped to handle this complication?
There are several different tax credits available to tax payers, in addition to the new hybrid tax credit. The total sum of all credits being claimed, cannot exceed the difference between the taxes you pay (1040 line 44), and the dreaded Alternative Minimum Tax (AMT). So, the one complication is having to actually calculate your AMT. More usually, AMT is something only the rich to had worry about, and I assume most of them have an accountant do their taxes.
I guess it is worse if you have other credits, too, like the Home Energy, Education, Adoption, etc.
I know I feel into this trap myself, and I will only be able to claim about 60% of the total hybrid credit allowed me, because of it.
