Thanks, Jerri.  I have finally received a call back from a higher level tech person who has asked me to submit my tax file and will begin looking into the error from the TTax Deluxe software perspective.  I am not a tax prepare professional, so this forum has done wonders to confirm that I am not crazy!

I fully understand how the stimulus payments are supposed to be applied to determine the figure in Line 10 of Oregon Form 40 and how the final effect depends on how much federal tax liability each person has.  I happen to be in the area where the stimulus payments subtraction take me below the Oregon maximum federal tax subtraction.  That's what alerted me to this subject in the first place!

Just for clarity for us TTax Deluxe individual filers:  When in the Federal section, there is a page for entering the amounts for both stimulus checks. All looks well and good there.  However, when proceeding to the Oregon form 40 section, the software only uses the FIRST stimulus check amount in the calculation in the worksheet entitled “Oregon Federal Tax Liability Subtraction Worksheet”.

You can verify that by going to the Forms link (upper right corner). Once the Forms window pops up on the left, scroll down to Oregon Individual and look for “Fed Tax Lib Wk”.
Click on that to open the worksheet. You should notice that only the FIRST stimulus payment is subtracted in the calculations, not both as should be.