Never had this problem dont mind the sides its the rubber top i don't like , my old diamondback 3g i use in work is still nice and matt however there are 2 shiny finger marks on the death adder
Its because you fingers don't sit flat like on the diamondback and there is more force on one point of the key wearing out the rubber finish. i miss my first gen diamondback with the clear top but i broke the USB plug sad sad day