I was having the low framerate in crysis 2 of 30-50 frames and the shadow blob problem, and then i fixed it, hopefully it works for you too, it was simple. i am running 5870 crossfire and i7920 stock clocks. catalyst 11.4 latest CAP. So go into single player and put all settings maxed v-sync on and start game, then after a few seconds playing i went back to the settings and changed only from extreme to very high and play a few more seconds then go back into settings and change back to extreme and i get in the hundreds in frames and runs perfect. works in multiplayer too. finally I got it to run right. oh yeah i have the steam version. hopefully this works for you too. nothing else worked for me.