Yip i got this problem with my GF3, i have to knock off Anti aliasing for Empire Earth cos i get the same prob but i then have to put it back on for FS2 so i don't get the "Jaggies" problem, i have also noticed that it only does this weird effect with Homeworld, empire earth and any other 3d stragey game unlike AVP2 and wolfenstien Anti aliasing is works brillantly on them. so maybe its something to do with the GF3s and i c that GF4s are rumoured to be released in feb.
"For 10,000 years we have thought the
long war and our hatred still knows no
succour. Those who have defied us shall
feel the full wrath of Chaos..."
-Abaddon the Despoiler.