Any league based anticheat, nothingtosee, wire, libra, eseaAC, easyanticheat. Obviously VAC won't ban you for it cos it's not hooked into the game, VAC is useless anyway 90% of private cheats bypass it. Zblock is working on a method to block AO users, with a system that detects when a smoke is deployed you cannot see anyone behind it. I don't know how far they have developed it. They did develop a system that stops users of Antiflash by makign player models disappear until the effects of the flash should have worn off. edit: zb_antismoke (Default: 0) - Counter-Strike: Source Only - When enabled players who are stood in the middle of a bloomed smoke grenade are not visible by the use of exploits. - Note: 0 = Disabled / 1 = Enabled. from http://zblock.mgamez.eu/readme.htm
well im pretty sure its an nVidia problem, ive used many ATI graphics cards on mw2, GTASA and CSS, however on nvidia mw2 Smoke is a hazy mist, GTA SA flying through clouses drops the framerate to 10-20, CSS looked way better on ATI when it comes to smoke :/