@climbon05 

Your result is what to expect from following Oregon published guidance. You can make up your own rule and phrase a question so that someone in Salem agrees with you, or you can wait until all Oregon taxpayers are told that there is a mistake in the instructions.

From Oregon Publication OR-17, page 65

The [federal tax] subtraction is based on the accrual method of accounting. This means you subtract the total amount of your federal tax liability after credits for the current tax year (not less than zero) as shown on your original return, regardless of when you pay it.