I have a 1280 by 720 premiere pro file, when i export the frame size changed, what to do?

I have a 1280 by 720 premiere pro file with movies that are 1280 by 720 in it. I want to export it (export movie, not adobe encoder because it gives me much worser quality than export movie) in the same size. But now the frame size has changed and it's greyed out and can't set it back to 1280 by 720. How do i export in 1280 by 720...?