AA problem with HD 4870

[Figroll]

Basically on some games, don't know if its all of them. I cant enable AA if i run a game at my native res of 1680x1050, it seems to allow it to work if i drop the res down to 1280x800 or 1440x900. Both games i have checked this with are half life 2 and mass effect. Will be trying to see if it works on empire total war later too as AA doesn't appear to want to work on it ether. I have two monitors set up but i don't think that's whats causing the problem as don't stretch the desktop or run the game on both screens.

Anyone know what the problem is? The screens both use VGA connections if that means anything

I'm using drivers 9.9, any help is much appreciated! =]

*Update* Was playing Rise and Fall at native res with Anti Aliasing so the problem only seems to be on some games. No-one know whats wrong?

[Figroll]

Guess nobody knows whats wrong then?

[k0nigen]

try setting your AA and AF to 'Application Controlled' in CCC, then setting your AA/AF settings within HL2
If that doesn't work, try it the other way around and force AA/AF through CCC

[Figroll]

Just put the MSAA to 4x in game and worked, cheers =]