Well I'm not going to start using a proxy just to play a game.
I tried turning off dynamic lighting and I'm still getting the lag in play.
I guess I have to try something else.
Mate when you start the launcher,click on options and you will see there what proxy you are using,it is the game proxy,then try what I said earlier,it will take you 5 minutes and could solve your problems,if not then you did only waste a little time.
im running e6750 oc'd 2.66ghz orig to 3.2ghz, 4gb ram, windows 7 x64 8800gt sli
without sli and everything set on the option just down from HIGH, i do have AA set to 16x and AF set to 32x i think it is or 16x(im at work at the moment,)whatever the highest setting is and i get 30fps-40fps with sli enabled i get a 60fps and above.