Weird Texture Flashing with Far Cry, Help!

[yoyomac]

I wanted to go back and play Far Cry since my nice new mac book pro will play it with high settings. I installed the game, got to patch 1.33 and when I ran the game, I get these crazy flashing textures all over the screen. It's only coming from the trees. I don't know what's going on. When I set the settings to medium it still does it. When I set the settings to low, it goes away. And it only does it when I'm in an outdoor area. Any help would be great. I tried overclocked and not overclocked but that didn't help.

If anyone has run into this problem, let me know.