In PS. 1.6.1.6 missing logo Cash on delivery (COD) when you must choose payment method. ( mozilla element inspector image path looks wrong).
simply because , P.S. 1.6.1.6 , does not find prestashop image cashondelivery.png : PNG image files. to find the right dir, P.S. see if there is PNG files, not jpg or gif. then simply upload file PNG in directory where there are already gif and jpg files. Try, then believe !!