Sorry for bumping this thread, but I'm fighting hard to get rid of city shimmering on my ATI card (5770). I'm still struggling with this, searching the forum for all the reports about this issue and I have not figured out a solution yet. This graphical glitch is important and breaks immersion for me. Have you found a solution? I've read reports of some success using Catalyst 10.5, but not tried it yet. I'm going to try this out and post the results.