The FW doesn't need to be 4.5 exactly, but it must be 4.x (4.1 - 4.5) because Gateway doesn't work on older and newer software. FW 4.5 is preferred because it's the lowest FW version for some high-profile games which won't run on lower 4.x FW; if none of the games you're interested in require 4.5, you can stay on lower 4.x as long as it supports everything you want to play.Also why does firmware need to be on 4.5 exactly, and not just any firmware release below 4.5?