why "confirm payment" when no payment owed (free form, refund)

I finished entering everything and was brought to the File page. On it, it shows a refund for both federal and state, and has recommended extras that I have not checked. I was able to use the free form because it is a very simple situation: single, employee, no special circumstances, no kids, no education, no health exchange purchases—no reason to have to pay anything since it says both the Federal and State filing are free with the simple form. Yet on this page, to continue, the only button is "Confirm Payment". I am afraid to proceed not knowing why it is asking me that. It doesn't show an amount. Does it always show that even if there is no payment needed? I went through the checklist I found online to make sure I didn't add anything, and I cant find anything that was added.