@ojbyrne - In your post in another thread you said that you enter the amount of the payment, but it doesn't flow to Form 1040 and it doesn't change the tax due.
Since you are using the download TurboTax software, please try this. Go to forms mode and open Form 4868. Below your name and address there is a box with the heading "Important Information." In that box there is a checkbox A. If that box is not checked, click it to check it. Then see if that makes your extension payment change your federal tax due.
Please let us know if this solves the problem.
