Para la descarga:
http://www.infinityward.com/modernwarfare/patch/
Básicamente mejoran problemas de lag y la precisón del rifle de sniper a ciertas distancias.
"This patch addresses the issue reported by community member Uzi Kidding which now catches some files bypassing the pure client test. In addition this update will set properties so that Anti-lag is always enabled upon map loads, an optimization for Sniper Rifle accuracty at certain distances, as well a fix so text chat between rounds of multiplayer will no longer cut out at the end. The 1.3 patch will also include all previous fixes from previous patches."
xDDD
